cc/trees/layer_tree_host_impl_unittest.cc

// Copyright 2011 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "cc/trees/layer_tree_host_impl.h"

#include <stddef.h>

#include <algorithm>
#include <cmath>
#include <utility>

#include "base/bind.h"
#include "base/command_line.h"
#include "base/location.h"
#include "base/thread_task_runner_handle.h"
#include "cc/animation/animation_events.h"
#include "cc/animation/animation_host.h"
#include "cc/animation/animation_id_provider.h"
#include "cc/animation/transform_operations.h"
#include "cc/base/math_util.h"
#include "cc/input/main_thread_scrolling_reason.h"
#include "cc/input/page_scale_animation.h"
#include "cc/input/scrollbar_animation_controller_thinning.h"
#include "cc/input/top_controls_manager.h"
#include "cc/layers/append_quads_data.h"
#include "cc/layers/heads_up_display_layer_impl.h"
#include "cc/layers/io_surface_layer_impl.h"
#include "cc/layers/layer_impl.h"
#include "cc/layers/painted_scrollbar_layer_impl.h"
#include "cc/layers/render_surface_impl.h"
#include "cc/layers/solid_color_layer_impl.h"
#include "cc/layers/solid_color_scrollbar_layer_impl.h"
#include "cc/layers/texture_layer_impl.h"
#include "cc/layers/video_layer_impl.h"
#include "cc/layers/viewport.h"
#include "cc/output/begin_frame_args.h"
#include "cc/output/compositor_frame_ack.h"
#include "cc/output/compositor_frame_metadata.h"
#include "cc/output/copy_output_request.h"
#include "cc/output/copy_output_result.h"
#include "cc/output/gl_renderer.h"
#include "cc/output/latency_info_swap_promise.h"
#include "cc/quads/render_pass_draw_quad.h"
#include "cc/quads/solid_color_draw_quad.h"
#include "cc/quads/texture_draw_quad.h"
#include "cc/quads/tile_draw_quad.h"
#include "cc/test/animation_test_common.h"
#include "cc/test/begin_frame_args_test.h"
#include "cc/test/fake_display_list_raster_source.h"
#include "cc/test/fake_layer_tree_host_impl.h"
#include "cc/test/fake_mask_layer_impl.h"
#include "cc/test/fake_output_surface.h"
#include "cc/test/fake_output_surface_client.h"
#include "cc/test/fake_picture_layer_impl.h"
#include "cc/test/fake_video_frame_provider.h"
#include "cc/test/geometry_test_utils.h"
#include "cc/test/gpu_rasterization_enabled_settings.h"
#include "cc/test/layer_test_common.h"
#include "cc/test/layer_tree_test.h"
#include "cc/test/test_gpu_memory_buffer_manager.h"
#include "cc/test/test_shared_bitmap_manager.h"
#include "cc/test/test_task_graph_runner.h"
#include "cc/test/test_web_graphics_context_3d.h"
#include "cc/trees/layer_tree_impl.h"
#include "cc/trees/single_thread_proxy.h"
#include "media/base/media.h"
#include "testing/gmock/include/gmock/gmock.h"
#include "testing/gtest/include/gtest/gtest.h"
#include "third_party/skia/include/core/SkMallocPixelRef.h"
#include "ui/gfx/geometry/rect_conversions.h"
#include "ui/gfx/geometry/size_conversions.h"
#include "ui/gfx/geometry/vector2d_conversions.h"

#define EXPECT_SCOPED(statements) \
  {                               \
    SCOPED_TRACE("");             \
    statements;                   \
  }

using ::testing::Mock;
using ::testing::Return;
using ::testing::AnyNumber;
using ::testing::AtLeast;
using ::testing::_;
using media::VideoFrame;

namespace cc {
namespace {

class LayerTreeHostImplTest : public testing::Test,
                              public LayerTreeHostImplClient {
 public:
  LayerTreeHostImplTest()
      : task_runner_provider_(base::ThreadTaskRunnerHandle::Get()),
        always_main_thread_blocked_(&task_runner_provider_),
        on_can_draw_state_changed_called_(false),
        did_notify_ready_to_activate_(false),
        did_request_commit_(false),
        did_request_redraw_(false),
        did_request_next_frame_(false),
        did_request_prepare_tiles_(false),
        did_complete_page_scale_animation_(false),
        reduce_memory_result_(true),
        skip_draw_layers_in_on_draw_(false) {
    media::InitializeMediaLibrary();
  }

  LayerTreeSettings DefaultSettings() {
    LayerTreeSettings settings;
    settings.minimum_occlusion_tracking_size = gfx::Size();
    settings.renderer_settings.texture_id_allocation_chunk_size = 1;
    settings.gpu_rasterization_enabled = true;
    return settings;
  }

  void SetUp() override {
    CreateHostImpl(DefaultSettings(), CreateOutputSurface());
  }

  void TearDown() override {}

  void UpdateRendererCapabilitiesOnImplThread() override {}
  void DidLoseOutputSurfaceOnImplThread() override {}
  void CommitVSyncParameters(base::TimeTicks timebase,
                             base::TimeDelta interval) override {}
  void SetEstimatedParentDrawTime(base::TimeDelta draw_time) override {}
  void DidSwapBuffersOnImplThread() override {}
  void DidSwapBuffersCompleteOnImplThread() override {}
  void OnCanDrawStateChanged(bool can_draw) override {
    on_can_draw_state_changed_called_ = true;
  }
  void NotifyReadyToActivate() override {
    did_notify_ready_to_activate_ = true;
    host_impl_->ActivateSyncTree();
  }
  void NotifyReadyToDraw() override {}
  void SetNeedsRedrawOnImplThread() override { did_request_redraw_ = true; }
  void SetNeedsRedrawRectOnImplThread(const gfx::Rect& damage_rect) override {
    did_request_redraw_ = true;
  }
  void SetNeedsOneBeginImplFrameOnImplThread() override {
    did_request_next_frame_ = true;
  }
  void SetNeedsPrepareTilesOnImplThread() override {
    did_request_prepare_tiles_ = true;
  }
  void SetNeedsCommitOnImplThread() override { did_request_commit_ = true; }
  void SetVideoNeedsBeginFrames(bool needs_begin_frames) override {}
  void PostAnimationEventsToMainThreadOnImplThread(
      scoped_ptr<AnimationEvents> events) override {}
  bool IsInsideDraw() override { return false; }
  void RenewTreePriority() override {}
  void PostDelayedAnimationTaskOnImplThread(const base::Closure& task,
                                            base::TimeDelta delay) override {
    animation_task_ = task;
    requested_animation_delay_ = delay;
  }
  void DidActivateSyncTree() override {}
  void WillPrepareTiles() override {}
  void DidPrepareTiles() override {}
  void DidCompletePageScaleAnimationOnImplThread() override {
    did_complete_page_scale_animation_ = true;
  }
  void OnDrawForOutputSurface(bool resourceless_software_draw) override {
    scoped_ptr<LayerTreeHostImpl::FrameData> frame(
        new LayerTreeHostImpl::FrameData);
    EXPECT_EQ(DRAW_SUCCESS, PrepareToDrawFrame(frame.get()));
    last_on_draw_render_passes_.clear();
    RenderPass::CopyAll(frame->render_passes, &last_on_draw_render_passes_);
    if (!skip_draw_layers_in_on_draw_)
      host_impl_->DrawLayers(frame.get());
    host_impl_->DidDrawAllLayers(*frame);
    host_impl_->SwapBuffers(*frame);
    last_on_draw_frame_ = std::move(frame);
  }
  void PostFrameTimingEventsOnImplThread(
      scoped_ptr<FrameTimingTracker::CompositeTimingSet> composite_events,
      scoped_ptr<FrameTimingTracker::MainFrameTimingSet> main_frame_events)
      override {}

  void set_reduce_memory_result(bool reduce_memory_result) {
    reduce_memory_result_ = reduce_memory_result;
  }

  virtual bool CreateHostImpl(const LayerTreeSettings& settings,
                              scoped_ptr<OutputSurface> output_surface) {
    return CreateHostImplWithTaskRunnerProvider(
        settings, std::move(output_surface), &task_runner_provider_);
  }

  virtual bool CreateHostImplWithTaskRunnerProvider(
      const LayerTreeSettings& settings,
      scoped_ptr<OutputSurface> output_surface,
      TaskRunnerProvider* task_runner_provider) {
    host_impl_ = LayerTreeHostImpl::Create(
        settings, this, task_runner_provider, &stats_instrumentation_,
        &shared_bitmap_manager_, &gpu_memory_buffer_manager_,
        &task_graph_runner_, 0);
    output_surface_ = std::move(output_surface);
    host_impl_->SetVisible(true);
    bool init = host_impl_->InitializeRenderer(output_surface_.get());
    host_impl_->SetViewportSize(gfx::Size(10, 10));
    host_impl_->active_tree()->PushPageScaleFromMainThread(1.f, 1.f, 1.f);
    // Set the BeginFrameArgs so that methods which use it are able to.
    host_impl_->WillBeginImplFrame(CreateBeginFrameArgsForTesting(
        BEGINFRAME_FROM_HERE,
        base::TimeTicks() + base::TimeDelta::FromMilliseconds(1)));
    host_impl_->DidFinishImplFrame();

    timeline_ =
        AnimationTimeline::Create(AnimationIdProvider::NextTimelineId());
    host_impl_->animation_host()->AddAnimationTimeline(timeline_);

    return init;
  }

  void SetupRootLayerImpl(scoped_ptr<LayerImpl> root) {
    root->SetPosition(gfx::PointF());
    root->SetBounds(gfx::Size(10, 10));
    root->SetDrawsContent(true);
    root->draw_properties().visible_layer_rect = gfx::Rect(0, 0, 10, 10);
    root->SetForceRenderSurface(true);
    host_impl_->active_tree()->SetRootLayer(std::move(root));
  }

  static gfx::Vector2dF ScrollDelta(LayerImpl* layer_impl) {
    gfx::ScrollOffset delta =
        layer_impl->layer_tree_impl()
            ->property_trees()
            ->scroll_tree.GetScrollOffsetDeltaForTesting(layer_impl->id());
    return gfx::Vector2dF(delta.x(), delta.y());
  }

  static void ExpectClearedScrollDeltasRecursive(LayerImpl* layer) {
    ASSERT_EQ(ScrollDelta(layer), gfx::Vector2d());
    for (size_t i = 0; i < layer->children().size(); ++i)
      ExpectClearedScrollDeltasRecursive(layer->children()[i].get());
  }

  static ::testing::AssertionResult ScrollInfoContains(
      const ScrollAndScaleSet& scroll_info,
      int id,
      const gfx::Vector2d& scroll_delta) {
    int times_encountered = 0;

    for (size_t i = 0; i < scroll_info.scrolls.size(); ++i) {
      if (scroll_info.scrolls[i].layer_id != id)
        continue;

      if (scroll_delta != scroll_info.scrolls[i].scroll_delta) {
        return ::testing::AssertionFailure()
               << "Expected " << scroll_delta.ToString() << ", not "
               << scroll_info.scrolls[i].scroll_delta.ToString();
      }
      times_encountered++;
    }

    if (times_encountered != 1)
      return ::testing::AssertionFailure() << "No layer found with id " << id;
    return ::testing::AssertionSuccess();
  }

  static void ExpectNone(const ScrollAndScaleSet& scroll_info, int id) {
    int times_encountered = 0;

    for (size_t i = 0; i < scroll_info.scrolls.size(); ++i) {
      if (scroll_info.scrolls[i].layer_id != id)
        continue;
      times_encountered++;
    }

    ASSERT_EQ(0, times_encountered);
  }

  LayerImpl* CreateScrollAndContentsLayers(LayerTreeImpl* layer_tree_impl,
                                           const gfx::Size& content_size) {
    // Create both an inner viewport scroll layer and an outer viewport scroll
    // layer. The MaxScrollOffset of the outer viewport scroll layer will be
    // 0x0, so the scrolls will be applied directly to the inner viewport.
    const int kOuterViewportClipLayerId = 116;
    const int kOuterViewportScrollLayerId = 117;
    const int kContentLayerId = 118;
    const int kInnerViewportScrollLayerId = 2;
    const int kInnerViewportClipLayerId = 4;
    const int kPageScaleLayerId = 5;

    scoped_ptr<LayerImpl> root =
        LayerImpl::Create(layer_tree_impl, 1);
    root->SetBounds(content_size);
    root->SetPosition(gfx::PointF());
    root->SetForceRenderSurface(true);

    scoped_ptr<LayerImpl> inner_scroll =
        LayerImpl::Create(layer_tree_impl, kInnerViewportScrollLayerId);
    inner_scroll->SetIsContainerForFixedPositionLayers(true);
    inner_scroll->layer_tree_impl()
        ->property_trees()
        ->scroll_tree.UpdateScrollOffsetBaseForTesting(inner_scroll->id(),
                                                       gfx::ScrollOffset());

    scoped_ptr<LayerImpl> inner_clip =
        LayerImpl::Create(layer_tree_impl, kInnerViewportClipLayerId);
    inner_clip->SetBounds(
        gfx::Size(content_size.width() / 2, content_size.height() / 2));

    scoped_ptr<LayerImpl> page_scale =
        LayerImpl::Create(layer_tree_impl, kPageScaleLayerId);

    inner_scroll->SetScrollClipLayer(inner_clip->id());
    inner_scroll->SetBounds(content_size);
    inner_scroll->SetPosition(gfx::PointF());

    scoped_ptr<LayerImpl> outer_clip =
        LayerImpl::Create(layer_tree_impl, kOuterViewportClipLayerId);
    outer_clip->SetBounds(content_size);
    outer_clip->SetIsContainerForFixedPositionLayers(true);

    scoped_ptr<LayerImpl> outer_scroll =
        LayerImpl::Create(layer_tree_impl, kOuterViewportScrollLayerId);
    outer_scroll->SetScrollClipLayer(outer_clip->id());
    outer_scroll->layer_tree_impl()
        ->property_trees()
        ->scroll_tree.UpdateScrollOffsetBaseForTesting(outer_scroll->id(),
                                                       gfx::ScrollOffset());
    outer_scroll->SetBounds(content_size);
    outer_scroll->SetPosition(gfx::PointF());

    scoped_ptr<LayerImpl> contents =
        LayerImpl::Create(layer_tree_impl, kContentLayerId);
    contents->SetDrawsContent(true);
    contents->SetBounds(content_size);
    contents->SetPosition(gfx::PointF());

    outer_scroll->AddChild(std::move(contents));
    outer_clip->AddChild(std::move(outer_scroll));
    inner_scroll->AddChild(std::move(outer_clip));
    page_scale->AddChild(std::move(inner_scroll));
    inner_clip->AddChild(std::move(page_scale));
    root->AddChild(std::move(inner_clip));

    layer_tree_impl->SetRootLayer(std::move(root));
    layer_tree_impl->SetViewportLayersFromIds(
        Layer::INVALID_ID, kPageScaleLayerId, kInnerViewportScrollLayerId,
        kOuterViewportScrollLayerId);

    layer_tree_impl->DidBecomeActive();
    return layer_tree_impl->InnerViewportScrollLayer();
  }

  LayerImpl* SetupScrollAndContentsLayers(const gfx::Size& content_size) {
    LayerImpl* scroll_layer = CreateScrollAndContentsLayers(
        host_impl_->active_tree(), content_size);
    SetNeedsRebuildPropertyTrees();
    RebuildPropertyTrees();
    host_impl_->active_tree()->DidBecomeActive();
    return scroll_layer;
  }

  // Sets up a typical virtual viewport setup with one child content layer.
  // Returns a pointer to the content layer.
  LayerImpl* CreateBasicVirtualViewportLayers(const gfx::Size& viewport_size,
                                              const gfx::Size& content_size) {
    // CreateScrollAndContentsLayers makes the outer viewport unscrollable and
    // the inner a different size from the outer. We'll reuse its layer
    // hierarchy but adjust the sizing to our needs.
    CreateScrollAndContentsLayers(host_impl_->active_tree(), content_size);

    LayerImpl* content_layer =
        host_impl_->OuterViewportScrollLayer()->children().back().get();
    content_layer->SetBounds(content_size);
    host_impl_->OuterViewportScrollLayer()->SetBounds(content_size);

    LayerImpl* outer_clip = host_impl_->OuterViewportScrollLayer()->parent();
    outer_clip->SetBounds(viewport_size);

    LayerImpl* inner_clip_layer =
        host_impl_->InnerViewportScrollLayer()->parent()->parent();
    inner_clip_layer->SetBounds(viewport_size);
    host_impl_->InnerViewportScrollLayer()->SetBounds(viewport_size);
    host_impl_->active_tree()->BuildPropertyTreesForTesting();

    host_impl_->SetViewportSize(viewport_size);
    host_impl_->active_tree()->DidBecomeActive();

    return content_layer;
  }

  scoped_ptr<LayerImpl> CreateScrollableLayer(int id,
                                              const gfx::Size& size,
                                              LayerImpl* clip_layer) {
    DCHECK(clip_layer);
    DCHECK(id != clip_layer->id());
    scoped_ptr<LayerImpl> layer =
        LayerImpl::Create(host_impl_->active_tree(), id);
    layer->SetScrollClipLayer(clip_layer->id());
    layer->SetDrawsContent(true);
    layer->SetBounds(size);
    clip_layer->SetBounds(gfx::Size(size.width() / 2, size.height() / 2));
    return layer;
  }

  scoped_ptr<ScrollState> BeginState(const gfx::Point& point) {
    ScrollStateData scroll_state_data;
    scroll_state_data.is_beginning = true;
    scroll_state_data.start_position_x = point.x();
    scroll_state_data.start_position_y = point.y();
    scoped_ptr<ScrollState> scroll_state(new ScrollState(scroll_state_data));
    return scroll_state;
  }

  scoped_ptr<ScrollState> UpdateState(const gfx::Point& point,
                                      const gfx::Vector2dF& delta) {
    ScrollStateData scroll_state_data;
    scroll_state_data.delta_x = delta.x();
    scroll_state_data.delta_y = delta.y();
    scroll_state_data.start_position_x = point.x();
    scroll_state_data.start_position_y = point.y();
    scoped_ptr<ScrollState> scroll_state(new ScrollState(scroll_state_data));
    return scroll_state;
  }

  scoped_ptr<ScrollState> EndState() {
    ScrollStateData scroll_state_data;
    scroll_state_data.is_ending = true;
    scoped_ptr<ScrollState> scroll_state(new ScrollState(scroll_state_data));
    return scroll_state;
  }

  void DrawFrame() {
    LayerTreeHostImpl::FrameData frame;
    EXPECT_EQ(DRAW_SUCCESS, PrepareToDrawFrame(&frame));
    host_impl_->DrawLayers(&frame);
    host_impl_->DidDrawAllLayers(frame);
  }

  void SetNeedsRebuildPropertyTrees() {
    host_impl_->active_tree()->property_trees()->needs_rebuild = true;
  }

  void RebuildPropertyTrees() {
    host_impl_->active_tree()->BuildPropertyTreesForTesting();
  }

  DrawResult PrepareToDrawFrame(LayerTreeHostImpl::FrameData* frame) {
    // We need to build property trees here before drawing the frame as they are
    // not built on the impl thread.
    RebuildPropertyTrees();
    return host_impl_->PrepareToDraw(frame);
  }

  void pinch_zoom_pan_viewport_forces_commit_redraw(float device_scale_factor);
  void pinch_zoom_pan_viewport_test(float device_scale_factor);
  void pinch_zoom_pan_viewport_and_scroll_test(float device_scale_factor);
  void pinch_zoom_pan_viewport_and_scroll_boundary_test(
      float device_scale_factor);

  void SetupMouseMoveAtWithDeviceScale(float device_scale_factor);

  scoped_refptr<AnimationTimeline> timeline() { return timeline_; }

 protected:
  virtual scoped_ptr<OutputSurface> CreateOutputSurface() {
    return FakeOutputSurface::Create3d();
  }

  void DrawOneFrame() {
    LayerTreeHostImpl::FrameData frame_data;
    PrepareToDrawFrame(&frame_data);
    host_impl_->DidDrawAllLayers(frame_data);
  }

  static void SetScrollOffsetDelta(LayerImpl* layer_impl,
                                   const gfx::Vector2dF& delta) {
    if (layer_impl->layer_tree_impl()
            ->property_trees()
            ->scroll_tree.SetScrollOffsetDeltaForTesting(layer_impl->id(),
                                                         delta))
      layer_impl->layer_tree_impl()->DidUpdateScrollOffset(
          layer_impl->id(), layer_impl->transform_tree_index());
  }

  FakeImplTaskRunnerProvider task_runner_provider_;
  DebugScopedSetMainThreadBlocked always_main_thread_blocked_;

  TestSharedBitmapManager shared_bitmap_manager_;
  TestGpuMemoryBufferManager gpu_memory_buffer_manager_;
  TestTaskGraphRunner task_graph_runner_;
  scoped_ptr<OutputSurface> output_surface_;
  scoped_ptr<LayerTreeHostImpl> host_impl_;
  FakeRenderingStatsInstrumentation stats_instrumentation_;
  bool on_can_draw_state_changed_called_;
  bool did_notify_ready_to_activate_;
  bool did_request_commit_;
  bool did_request_redraw_;
  bool did_request_next_frame_;
  bool did_request_prepare_tiles_;
  bool did_complete_page_scale_animation_;
  bool reduce_memory_result_;
  base::Closure animation_task_;
  base::TimeDelta requested_animation_delay_;
  bool skip_draw_layers_in_on_draw_;
  scoped_ptr<LayerTreeHostImpl::FrameData> last_on_draw_frame_;
  RenderPassList last_on_draw_render_passes_;
  scoped_refptr<AnimationTimeline> timeline_;
};

// A test fixture for new animation timelines tests.
class LayerTreeHostImplTimelinesTest : public LayerTreeHostImplTest {
 public:
  void SetUp() override {
    CreateHostImpl(DefaultSettings(), CreateOutputSurface());
  }
};

TEST_F(LayerTreeHostImplTest, NotifyIfCanDrawChanged) {
  // Note: It is not possible to disable the renderer once it has been set,
  // so we do not need to test that disabling the renderer notifies us
  // that can_draw changed.
  EXPECT_FALSE(host_impl_->CanDraw());
  on_can_draw_state_changed_called_ = false;

  // Set up the root layer, which allows us to draw.
  SetupScrollAndContentsLayers(gfx::Size(100, 100));
  EXPECT_TRUE(host_impl_->CanDraw());
  EXPECT_TRUE(on_can_draw_state_changed_called_);
  on_can_draw_state_changed_called_ = false;

  // Toggle the root layer to make sure it toggles can_draw
  host_impl_->active_tree()->SetRootLayer(nullptr);
  EXPECT_FALSE(host_impl_->CanDraw());
  EXPECT_TRUE(on_can_draw_state_changed_called_);
  on_can_draw_state_changed_called_ = false;

  SetupScrollAndContentsLayers(gfx::Size(100, 100));
  EXPECT_TRUE(host_impl_->CanDraw());
  EXPECT_TRUE(on_can_draw_state_changed_called_);
  on_can_draw_state_changed_called_ = false;

  // Toggle the device viewport size to make sure it toggles can_draw.
  host_impl_->SetViewportSize(gfx::Size());
  EXPECT_FALSE(host_impl_->CanDraw());
  EXPECT_TRUE(on_can_draw_state_changed_called_);
  on_can_draw_state_changed_called_ = false;

  host_impl_->SetViewportSize(gfx::Size(100, 100));
  EXPECT_TRUE(host_impl_->CanDraw());
  EXPECT_TRUE(on_can_draw_state_changed_called_);
  on_can_draw_state_changed_called_ = false;
}

TEST_F(LayerTreeHostImplTest, ResourcelessDrawWithEmptyViewport) {
  CreateHostImpl(DefaultSettings(),
                 FakeOutputSurface::CreateSoftware(
                     make_scoped_ptr(new SoftwareOutputDevice())));
  SetupScrollAndContentsLayers(gfx::Size(100, 100));
  EXPECT_TRUE(host_impl_->CanDraw());
  host_impl_->SetViewportSize(gfx::Size());
  EXPECT_FALSE(host_impl_->CanDraw());

  FakeOutputSurface* fake_output_surface =
      static_cast<FakeOutputSurface*>(host_impl_->output_surface());
  EXPECT_EQ(fake_output_surface->num_sent_frames(), 0u);
  gfx::Transform identity;
  gfx::Rect viewport(100, 100);
  const bool resourceless_software_draw = true;
  host_impl_->OnDraw(identity, viewport, viewport, resourceless_software_draw);
  ASSERT_EQ(fake_output_surface->num_sent_frames(), 1u);
  EXPECT_EQ(gfx::SizeF(100.f, 100.f),
            fake_output_surface->last_sent_frame().metadata.root_layer_size);
}

TEST_F(LayerTreeHostImplTest, ScrollDeltaNoLayers) {
  ASSERT_FALSE(host_impl_->active_tree()->root_layer());

  scoped_ptr<ScrollAndScaleSet> scroll_info = host_impl_->ProcessScrollDeltas();
  ASSERT_EQ(scroll_info->scrolls.size(), 0u);
}

TEST_F(LayerTreeHostImplTest, ScrollDeltaTreeButNoChanges) {
  {
    scoped_ptr<LayerImpl> root =
        LayerImpl::Create(host_impl_->active_tree(), 1);
    root->AddChild(LayerImpl::Create(host_impl_->active_tree(), 2));
    root->AddChild(LayerImpl::Create(host_impl_->active_tree(), 3));
    root->children()[1]->AddChild(
        LayerImpl::Create(host_impl_->active_tree(), 4));
    root->children()[1]->AddChild(
        LayerImpl::Create(host_impl_->active_tree(), 5));
    root->children()[1]->children()[0]->AddChild(
        LayerImpl::Create(host_impl_->active_tree(), 6));
    host_impl_->active_tree()->SetRootLayer(std::move(root));
  }
  LayerImpl* root = host_impl_->active_tree()->root_layer();

  ExpectClearedScrollDeltasRecursive(root);

  scoped_ptr<ScrollAndScaleSet> scroll_info;

  scroll_info = host_impl_->ProcessScrollDeltas();
  ASSERT_EQ(scroll_info->scrolls.size(), 0u);
  ExpectClearedScrollDeltasRecursive(root);

  scroll_info = host_impl_->ProcessScrollDeltas();
  ASSERT_EQ(scroll_info->scrolls.size(), 0u);
  ExpectClearedScrollDeltasRecursive(root);
}

TEST_F(LayerTreeHostImplTest, ScrollDeltaRepeatedScrolls) {
  gfx::ScrollOffset scroll_offset(20, 30);
  gfx::Vector2d scroll_delta(11, -15);
  {
    scoped_ptr<LayerImpl> root_clip =
        LayerImpl::Create(host_impl_->active_tree(), 2);
    scoped_ptr<LayerImpl> root =
        LayerImpl::Create(host_impl_->active_tree(), 1);
    root_clip->SetBounds(gfx::Size(10, 10));
    LayerImpl* root_layer = root.get();
    root_clip->AddChild(std::move(root));
    root_layer->SetBounds(gfx::Size(110, 110));
    root_layer->SetScrollClipLayer(root_clip->id());
    root_layer->layer_tree_impl()
        ->property_trees()
        ->scroll_tree.UpdateScrollOffsetBaseForTesting(root_layer->id(),
                                                       scroll_offset);
    host_impl_->active_tree()->SetRootLayer(std::move(root_clip));
    host_impl_->active_tree()->BuildPropertyTreesForTesting();
    root_layer->ScrollBy(scroll_delta);
  }

  LayerImpl* root =
      host_impl_->active_tree()->root_layer()->children()[0].get();

  scoped_ptr<ScrollAndScaleSet> scroll_info;

  scroll_info = host_impl_->ProcessScrollDeltas();
  ASSERT_EQ(scroll_info->scrolls.size(), 1u);
  EXPECT_TRUE(ScrollInfoContains(*scroll_info, root->id(), scroll_delta));

  gfx::Vector2d scroll_delta2(-5, 27);
  root->ScrollBy(scroll_delta2);
  scroll_info = host_impl_->ProcessScrollDeltas();
  ASSERT_EQ(scroll_info->scrolls.size(), 1u);
  EXPECT_TRUE(ScrollInfoContains(*scroll_info, root->id(),
                                 scroll_delta + scroll_delta2));

  root->ScrollBy(gfx::Vector2d());
  scroll_info = host_impl_->ProcessScrollDeltas();
  EXPECT_TRUE(ScrollInfoContains(*scroll_info, root->id(),
                                 scroll_delta + scroll_delta2));
}

TEST_F(LayerTreeHostImplTest, ScrollRootCallsCommitAndRedraw) {
  SetupScrollAndContentsLayers(gfx::Size(100, 100));
  host_impl_->SetViewportSize(gfx::Size(50, 50));
  DrawFrame();

  InputHandler::ScrollStatus status = host_impl_->ScrollBegin(
      BeginState(gfx::Point()).get(), InputHandler::WHEEL);
  EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD, status.thread);
  EXPECT_EQ(MainThreadScrollingReason::kNotScrollingOnMain,
            status.main_thread_scrolling_reasons);

  EXPECT_TRUE(host_impl_->IsCurrentlyScrollingLayerAt(gfx::Point(),
                                                      InputHandler::WHEEL));
  host_impl_->ScrollBy(UpdateState(gfx::Point(), gfx::Vector2d(0, 10)).get());
  EXPECT_TRUE(host_impl_->IsCurrentlyScrollingLayerAt(gfx::Point(0, 10),
                                                      InputHandler::WHEEL));
  host_impl_->ScrollEnd(EndState().get());
  EXPECT_FALSE(host_impl_->IsCurrentlyScrollingLayerAt(gfx::Point(),
                                                       InputHandler::WHEEL));
  EXPECT_TRUE(did_request_redraw_);
  EXPECT_TRUE(did_request_commit_);
}

TEST_F(LayerTreeHostImplTest, ScrollActiveOnlyAfterScrollMovement) {
  SetupScrollAndContentsLayers(gfx::Size(100, 100));
  host_impl_->SetViewportSize(gfx::Size(50, 50));
  DrawFrame();

  InputHandler::ScrollStatus status = host_impl_->ScrollBegin(
      BeginState(gfx::Point()).get(), InputHandler::WHEEL);
  EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD, status.thread);
  EXPECT_EQ(MainThreadScrollingReason::kNotScrollingOnMain,
            status.main_thread_scrolling_reasons);

  EXPECT_FALSE(host_impl_->IsActivelyScrolling());
  host_impl_->ScrollBy(UpdateState(gfx::Point(), gfx::Vector2d(0, 10)).get());
  EXPECT_TRUE(host_impl_->IsActivelyScrolling());
  host_impl_->ScrollEnd(EndState().get());
  EXPECT_FALSE(host_impl_->IsActivelyScrolling());
}

TEST_F(LayerTreeHostImplTest, ScrollWithoutRootLayer) {
  // We should not crash when trying to scroll an empty layer tree.
  InputHandler::ScrollStatus status = host_impl_->ScrollBegin(
      BeginState(gfx::Point()).get(), InputHandler::WHEEL);
  EXPECT_EQ(InputHandler::SCROLL_IGNORED, status.thread);
  EXPECT_EQ(MainThreadScrollingReason::kNoScrollingLayer,
            status.main_thread_scrolling_reasons);
}

TEST_F(LayerTreeHostImplTest, ScrollWithoutRenderer) {
  scoped_ptr<TestWebGraphicsContext3D> context_owned =
      TestWebGraphicsContext3D::Create();
  context_owned->set_context_lost(true);

  // Initialization will fail.
  EXPECT_FALSE(
      CreateHostImpl(DefaultSettings(),
                     FakeOutputSurface::Create3d(std::move(context_owned))));

  SetupScrollAndContentsLayers(gfx::Size(100, 100));

  // We should not crash when trying to scroll after the renderer initialization
  // fails.
  InputHandler::ScrollStatus status = host_impl_->ScrollBegin(
      BeginState(gfx::Point()).get(), InputHandler::WHEEL);
  EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD, status.thread);
  EXPECT_EQ(MainThreadScrollingReason::kNotScrollingOnMain,
            status.main_thread_scrolling_reasons);
}

TEST_F(LayerTreeHostImplTest, ReplaceTreeWhileScrolling) {
  LayerImpl* scroll_layer = SetupScrollAndContentsLayers(gfx::Size(100, 100));
  host_impl_->SetViewportSize(gfx::Size(50, 50));
  DrawFrame();

  // We should not crash if the tree is replaced while we are scrolling.
  EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
            host_impl_->ScrollBegin(BeginState(gfx::Point()).get(),
                                    InputHandler::WHEEL)
                .thread);
  host_impl_->active_tree()->DetachLayerTree();

  scroll_layer = SetupScrollAndContentsLayers(gfx::Size(100, 100));

  // We should still be scrolling, because the scrolled layer also exists in the
  // new tree.
  gfx::Vector2d scroll_delta(0, 10);
  host_impl_->ScrollBy(UpdateState(gfx::Point(), scroll_delta).get());
  host_impl_->ScrollEnd(EndState().get());
  scoped_ptr<ScrollAndScaleSet> scroll_info = host_impl_->ProcessScrollDeltas();
  EXPECT_TRUE(
      ScrollInfoContains(*scroll_info, scroll_layer->id(), scroll_delta));
}

TEST_F(LayerTreeHostImplTest, ScrollBlocksOnWheelEventHandlers) {
  SetupScrollAndContentsLayers(gfx::Size(100, 100));
  host_impl_->SetViewportSize(gfx::Size(50, 50));
  DrawFrame();

  // With registered event handlers, wheel scrolls don't necessarily
  // have to go to the main thread.
  host_impl_->active_tree()->set_event_listener_properties(
      EventListenerClass::kMouseWheel, EventListenerProperties::kBlocking);
  InputHandler::ScrollStatus status =
    host_impl_->ScrollBegin(BeginState(gfx::Point()).get(),
                                   InputHandler::WHEEL);
  EXPECT_EQ(InputHandler::SCROLL_ON_MAIN_THREAD, status.thread);
  EXPECT_EQ(MainThreadScrollingReason::kEventHandlers,
            status.main_thread_scrolling_reasons);

  host_impl_->active_tree()->set_event_listener_properties(
      EventListenerClass::kMouseWheel,
      EventListenerProperties::kBlockingAndPassive);
  status = host_impl_->ScrollBegin(BeginState(gfx::Point()).get(),
                                   InputHandler::WHEEL);
  EXPECT_EQ(InputHandler::SCROLL_ON_MAIN_THREAD, status.thread);
  EXPECT_EQ(MainThreadScrollingReason::kEventHandlers,
            status.main_thread_scrolling_reasons);

  // But gesture scrolls can still be handled.
  status = host_impl_->ScrollBegin(BeginState(gfx::Point()).get(),
                                   InputHandler::TOUCHSCREEN);
  EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD, status.thread);
  EXPECT_EQ(MainThreadScrollingReason::kNotScrollingOnMain,
            status.main_thread_scrolling_reasons);
  host_impl_->ScrollEnd(EndState().get());

  // And if the handlers go away, wheel scrolls can again be processed
  // on impl.
  host_impl_->active_tree()->set_event_listener_properties(
      EventListenerClass::kMouseWheel, EventListenerProperties::kNone);
  status = host_impl_->ScrollBegin(BeginState(gfx::Point()).get(),
                                   InputHandler::WHEEL);
  EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD, status.thread);
  EXPECT_EQ(MainThreadScrollingReason::kNotScrollingOnMain,
            status.main_thread_scrolling_reasons);
  host_impl_->ScrollEnd(EndState().get());
}

TEST_F(LayerTreeHostImplTest, ScrollBlocksOnTouchEventHandlers) {
  LayerImpl* scroll = SetupScrollAndContentsLayers(gfx::Size(100, 100));
  host_impl_->SetViewportSize(gfx::Size(50, 50));
  DrawFrame();
  LayerImpl* root = host_impl_->active_tree()->root_layer();

  LayerImpl* child = 0;
  {
    scoped_ptr<LayerImpl> child_layer =
        LayerImpl::Create(host_impl_->active_tree(), 6);
    child = child_layer.get();
    child_layer->SetDrawsContent(true);
    child_layer->SetPosition(gfx::PointF(0, 20));
    child_layer->SetBounds(gfx::Size(50, 50));
    scroll->AddChild(std::move(child_layer));
    SetNeedsRebuildPropertyTrees();
    RebuildPropertyTrees();
  }

  // Touch handler regions determine whether touch events block scroll.
  root->SetTouchEventHandlerRegion(gfx::Rect(0, 0, 100, 100));
  EXPECT_TRUE(host_impl_->DoTouchEventsBlockScrollAt(gfx::Point(10, 10)));

  // But they don't influence the actual handling of the scroll gestures.
  InputHandler::ScrollStatus status = host_impl_->ScrollBegin(
      BeginState(gfx::Point()).get(), InputHandler::TOUCHSCREEN);
  EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD, status.thread);
  EXPECT_EQ(MainThreadScrollingReason::kNotScrollingOnMain,
            status.main_thread_scrolling_reasons);
  host_impl_->ScrollEnd(EndState().get());

  EXPECT_TRUE(host_impl_->DoTouchEventsBlockScrollAt(gfx::Point(10, 30)));
  root->SetTouchEventHandlerRegion(gfx::Rect());
  EXPECT_FALSE(host_impl_->DoTouchEventsBlockScrollAt(gfx::Point(10, 30)));
  child->SetTouchEventHandlerRegion(gfx::Rect(0, 0, 50, 50));
  EXPECT_TRUE(host_impl_->DoTouchEventsBlockScrollAt(gfx::Point(10, 30)));
}

TEST_F(LayerTreeHostImplTest, FlingOnlyWhenScrollingTouchscreen) {
  SetupScrollAndContentsLayers(gfx::Size(100, 100));
  host_impl_->SetViewportSize(gfx::Size(50, 50));
  DrawFrame();

  // Ignore the fling since no layer is being scrolled
  InputHandler::ScrollStatus status = host_impl_->FlingScrollBegin();
  EXPECT_EQ(InputHandler::SCROLL_IGNORED, status.thread);
  EXPECT_EQ(MainThreadScrollingReason::kNoScrollingLayer,
            status.main_thread_scrolling_reasons);

  // Start scrolling a layer
  status = host_impl_->ScrollBegin(BeginState(gfx::Point()).get(),
                                   InputHandler::TOUCHSCREEN);
  EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD, status.thread);
  EXPECT_EQ(MainThreadScrollingReason::kNotScrollingOnMain,
            status.main_thread_scrolling_reasons);

  // Now the fling should go ahead since we've started scrolling a layer
  status = host_impl_->FlingScrollBegin();
  EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD, status.thread);
  EXPECT_EQ(MainThreadScrollingReason::kNotScrollingOnMain,
            status.main_thread_scrolling_reasons);
}

TEST_F(LayerTreeHostImplTest, FlingOnlyWhenScrollingTouchpad) {
  SetupScrollAndContentsLayers(gfx::Size(100, 100));
  host_impl_->SetViewportSize(gfx::Size(50, 50));
  DrawFrame();

  // Ignore the fling since no layer is being scrolled
  InputHandler::ScrollStatus status = host_impl_->FlingScrollBegin();
  EXPECT_EQ(InputHandler::SCROLL_IGNORED, status.thread);
  EXPECT_EQ(MainThreadScrollingReason::kNoScrollingLayer,
            status.main_thread_scrolling_reasons);

  // Start scrolling a layer
  status = host_impl_->ScrollBegin(BeginState(gfx::Point()).get(),
                                   InputHandler::WHEEL);
  EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD, status.thread);
  EXPECT_EQ(MainThreadScrollingReason::kNotScrollingOnMain,
            status.main_thread_scrolling_reasons);

  // Now the fling should go ahead since we've started scrolling a layer
  status = host_impl_->FlingScrollBegin();
  EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD, status.thread);
  EXPECT_EQ(MainThreadScrollingReason::kNotScrollingOnMain,
            status.main_thread_scrolling_reasons);
}

TEST_F(LayerTreeHostImplTest, NoFlingWhenScrollingOnMain) {
  SetupScrollAndContentsLayers(gfx::Size(100, 100));
  host_impl_->SetViewportSize(gfx::Size(50, 50));
  LayerImpl* root = host_impl_->active_tree()->root_layer();

  root->set_main_thread_scrolling_reasons(
      MainThreadScrollingReason::kHasBackgroundAttachmentFixedObjects);

  SetNeedsRebuildPropertyTrees();
  DrawFrame();

  // Start scrolling a layer
  InputHandler::ScrollStatus status = host_impl_->ScrollBegin(
      BeginState(gfx::Point()).get(), InputHandler::TOUCHSCREEN);
  EXPECT_EQ(InputHandler::SCROLL_ON_MAIN_THREAD, status.thread);
  EXPECT_EQ(MainThreadScrollingReason::kHasBackgroundAttachmentFixedObjects,
            status.main_thread_scrolling_reasons);

  // The fling should be ignored since there's no layer being scrolled impl-side
  status = host_impl_->FlingScrollBegin();
  EXPECT_EQ(InputHandler::SCROLL_IGNORED, status.thread);
  EXPECT_EQ(MainThreadScrollingReason::kNoScrollingLayer,
            status.main_thread_scrolling_reasons);
}

TEST_F(LayerTreeHostImplTest, ShouldScrollOnMainThread) {
  SetupScrollAndContentsLayers(gfx::Size(100, 100));
  host_impl_->SetViewportSize(gfx::Size(50, 50));
  LayerImpl* root = host_impl_->active_tree()->root_layer();

  root->set_main_thread_scrolling_reasons(
      MainThreadScrollingReason::kHasBackgroundAttachmentFixedObjects);
  SetNeedsRebuildPropertyTrees();
  DrawFrame();

  InputHandler::ScrollStatus status = host_impl_->ScrollBegin(
      BeginState(gfx::Point()).get(), InputHandler::WHEEL);
  EXPECT_EQ(InputHandler::SCROLL_ON_MAIN_THREAD, status.thread);
  EXPECT_EQ(MainThreadScrollingReason::kHasBackgroundAttachmentFixedObjects,
            status.main_thread_scrolling_reasons);

  status = host_impl_->ScrollBegin(BeginState(gfx::Point()).get(),
                                   InputHandler::TOUCHSCREEN);
  EXPECT_EQ(InputHandler::SCROLL_ON_MAIN_THREAD, status.thread);
  EXPECT_EQ(MainThreadScrollingReason::kHasBackgroundAttachmentFixedObjects,
            status.main_thread_scrolling_reasons);
}

TEST_F(LayerTreeHostImplTest, NonFastScrollableRegionBasic) {
  SetupScrollAndContentsLayers(gfx::Size(200, 200));
  host_impl_->SetViewportSize(gfx::Size(100, 100));

  LayerImpl* root = host_impl_->active_tree()->root_layer();
  root->SetNonFastScrollableRegion(gfx::Rect(0, 0, 50, 50));

  SetNeedsRebuildPropertyTrees();
  DrawFrame();

  // All scroll types inside the non-fast scrollable region should fail.
  InputHandler::ScrollStatus status = host_impl_->ScrollBegin(
      BeginState(gfx::Point(25, 25)).get(), InputHandler::WHEEL);
  EXPECT_EQ(InputHandler::SCROLL_ON_MAIN_THREAD, status.thread);
  EXPECT_EQ(MainThreadScrollingReason::kNonFastScrollableRegion,
            status.main_thread_scrolling_reasons);
  EXPECT_FALSE(host_impl_->IsCurrentlyScrollingLayerAt(gfx::Point(25, 25),
                                                       InputHandler::WHEEL));

  status = host_impl_->ScrollBegin(BeginState(gfx::Point(25, 25)).get(),
                                   InputHandler::TOUCHSCREEN);
  EXPECT_EQ(InputHandler::SCROLL_ON_MAIN_THREAD, status.thread);
  EXPECT_EQ(MainThreadScrollingReason::kNonFastScrollableRegion,
            status.main_thread_scrolling_reasons);
  EXPECT_FALSE(host_impl_->IsCurrentlyScrollingLayerAt(
      gfx::Point(25, 25), InputHandler::TOUCHSCREEN));

  // All scroll types outside this region should succeed.
  status = host_impl_->ScrollBegin(BeginState(gfx::Point(75, 75)).get(),
                                   InputHandler::WHEEL);
  EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD, status.thread);
  EXPECT_EQ(MainThreadScrollingReason::kNotScrollingOnMain,
            status.main_thread_scrolling_reasons);

  EXPECT_TRUE(host_impl_->IsCurrentlyScrollingLayerAt(
      gfx::Point(75, 75), InputHandler::TOUCHSCREEN));
  host_impl_->ScrollBy(UpdateState(gfx::Point(), gfx::Vector2d(0, 10)).get());
  EXPECT_FALSE(host_impl_->IsCurrentlyScrollingLayerAt(
      gfx::Point(25, 25), InputHandler::TOUCHSCREEN));
  host_impl_->ScrollEnd(EndState().get());
  EXPECT_FALSE(host_impl_->IsCurrentlyScrollingLayerAt(
      gfx::Point(75, 75), InputHandler::TOUCHSCREEN));

  status = host_impl_->ScrollBegin(BeginState(gfx::Point(75, 75)).get(),
                                   InputHandler::TOUCHSCREEN);
  EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD, status.thread);
  EXPECT_EQ(MainThreadScrollingReason::kNotScrollingOnMain,
            status.main_thread_scrolling_reasons);
  EXPECT_TRUE(host_impl_->IsCurrentlyScrollingLayerAt(
      gfx::Point(75, 75), InputHandler::TOUCHSCREEN));
  host_impl_->ScrollBy(UpdateState(gfx::Point(), gfx::Vector2d(0, 10)).get());
  host_impl_->ScrollEnd(EndState().get());
  EXPECT_FALSE(host_impl_->IsCurrentlyScrollingLayerAt(
      gfx::Point(75, 75), InputHandler::TOUCHSCREEN));
}

TEST_F(LayerTreeHostImplTest, NonFastScrollableRegionWithOffset) {
  SetupScrollAndContentsLayers(gfx::Size(200, 200));
  host_impl_->SetViewportSize(gfx::Size(100, 100));

  LayerImpl* root = host_impl_->active_tree()->root_layer();
  root->SetNonFastScrollableRegion(gfx::Rect(0, 0, 50, 50));
  root->SetPosition(gfx::PointF(-25.f, 0.f));
  root->SetDrawsContent(true);

  SetNeedsRebuildPropertyTrees();
  DrawFrame();

  // This point would fall into the non-fast scrollable region except that we've
  // moved the layer down by 25 pixels.
  InputHandler::ScrollStatus status = host_impl_->ScrollBegin(
      BeginState(gfx::Point(40, 10)).get(), InputHandler::WHEEL);
  EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD, status.thread);
  EXPECT_EQ(MainThreadScrollingReason::kNotScrollingOnMain,
            status.main_thread_scrolling_reasons);

  EXPECT_TRUE(host_impl_->IsCurrentlyScrollingLayerAt(gfx::Point(40, 10),
                                                      InputHandler::WHEEL));
  host_impl_->ScrollBy(UpdateState(gfx::Point(), gfx::Vector2d(0, 1)).get());
  host_impl_->ScrollEnd(EndState().get());

  // This point is still inside the non-fast region.
  status = host_impl_->ScrollBegin(BeginState(gfx::Point(10, 10)).get(),
                                   InputHandler::WHEEL);
  EXPECT_EQ(InputHandler::SCROLL_ON_MAIN_THREAD, status.thread);
  EXPECT_EQ(MainThreadScrollingReason::kNonFastScrollableRegion,
            status.main_thread_scrolling_reasons);
}

TEST_F(LayerTreeHostImplTest, ScrollHandlerNotPresent) {
  SetupScrollAndContentsLayers(gfx::Size(200, 200));
  EXPECT_FALSE(host_impl_->active_tree()->have_scroll_event_handlers());
  host_impl_->SetViewportSize(gfx::Size(50, 50));
  DrawFrame();

  EXPECT_FALSE(host_impl_->scroll_affects_scroll_handler());
  host_impl_->ScrollBegin(BeginState(gfx::Point()).get(),
                          InputHandler::TOUCHSCREEN);
  EXPECT_FALSE(host_impl_->scroll_affects_scroll_handler());
  host_impl_->ScrollEnd(EndState().get());
  EXPECT_FALSE(host_impl_->scroll_affects_scroll_handler());
}

TEST_F(LayerTreeHostImplTest, ScrollHandlerPresent) {
  SetupScrollAndContentsLayers(gfx::Size(200, 200));
  host_impl_->active_tree()->set_have_scroll_event_handlers(true);
  host_impl_->SetViewportSize(gfx::Size(50, 50));
  DrawFrame();

  EXPECT_FALSE(host_impl_->scroll_affects_scroll_handler());
  host_impl_->ScrollBegin(BeginState(gfx::Point()).get(),
                          InputHandler::TOUCHSCREEN);
  EXPECT_TRUE(host_impl_->scroll_affects_scroll_handler());
  host_impl_->ScrollEnd(EndState().get());
  EXPECT_FALSE(host_impl_->scroll_affects_scroll_handler());
}

TEST_F(LayerTreeHostImplTest, ScrollByReturnsCorrectValue) {
  SetupScrollAndContentsLayers(gfx::Size(200, 200));
  host_impl_->SetViewportSize(gfx::Size(100, 100));

  DrawFrame();

  InputHandler::ScrollStatus status = host_impl_->ScrollBegin(
      BeginState(gfx::Point()).get(), InputHandler::TOUCHSCREEN);
  EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD, status.thread);
  EXPECT_EQ(MainThreadScrollingReason::kNotScrollingOnMain,
            status.main_thread_scrolling_reasons);

  // Trying to scroll to the left/top will not succeed.
  EXPECT_FALSE(
      host_impl_->ScrollBy(
                    UpdateState(gfx::Point(), gfx::Vector2d(-10, 0)).get())
          .did_scroll);
  EXPECT_FALSE(
      host_impl_->ScrollBy(
                    UpdateState(gfx::Point(), gfx::Vector2d(0, -10)).get())
          .did_scroll);
  EXPECT_FALSE(
      host_impl_->ScrollBy(
                    UpdateState(gfx::Point(), gfx::Vector2d(-10, -10)).get())
          .did_scroll);

  // Scrolling to the right/bottom will succeed.
  EXPECT_TRUE(
      host_impl_->ScrollBy(
                    UpdateState(gfx::Point(), gfx::Vector2d(10, 0)).get())
          .did_scroll);
  EXPECT_TRUE(
      host_impl_->ScrollBy(
                    UpdateState(gfx::Point(), gfx::Vector2d(0, 10)).get())
          .did_scroll);
  EXPECT_TRUE(
      host_impl_->ScrollBy(
                    UpdateState(gfx::Point(), gfx::Vector2d(10, 10)).get())
          .did_scroll);

  // Scrolling to left/top will now succeed.
  EXPECT_TRUE(
      host_impl_->ScrollBy(
                    UpdateState(gfx::Point(), gfx::Vector2d(-10, 0)).get())
          .did_scroll);
  EXPECT_TRUE(
      host_impl_->ScrollBy(
                    UpdateState(gfx::Point(), gfx::Vector2d(0, -10)).get())
          .did_scroll);
  EXPECT_TRUE(
      host_impl_->ScrollBy(
                    UpdateState(gfx::Point(), gfx::Vector2d(-10, -10)).get())
          .did_scroll);

  // Scrolling diagonally against an edge will succeed.
  EXPECT_TRUE(
      host_impl_->ScrollBy(
                    UpdateState(gfx::Point(), gfx::Vector2d(10, -10)).get())
          .did_scroll);
  EXPECT_TRUE(
      host_impl_->ScrollBy(
                    UpdateState(gfx::Point(), gfx::Vector2d(-10, 0)).get())
          .did_scroll);
  EXPECT_TRUE(
      host_impl_->ScrollBy(
                    UpdateState(gfx::Point(), gfx::Vector2d(-10, 10)).get())
          .did_scroll);

  // Trying to scroll more than the available space will also succeed.
  EXPECT_TRUE(
      host_impl_->ScrollBy(
                    UpdateState(gfx::Point(), gfx::Vector2d(5000, 5000)).get())
          .did_scroll);
}

TEST_F(LayerTreeHostImplTest, ScrollVerticallyByPageReturnsCorrectValue) {
  SetupScrollAndContentsLayers(gfx::Size(200, 2000));
  host_impl_->SetViewportSize(gfx::Size(100, 1000));

  DrawFrame();

  EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
            host_impl_->ScrollBegin(BeginState(gfx::Point()).get(),
                                    InputHandler::WHEEL)
                .thread);

  // Trying to scroll if not user_scrollable_vertical will fail.
  host_impl_->InnerViewportScrollLayer()->set_user_scrollable_vertical(false);
  SetNeedsRebuildPropertyTrees();
  DrawFrame();
  EXPECT_FALSE(host_impl_->ScrollVerticallyByPage(
      gfx::Point(), SCROLL_FORWARD));
  EXPECT_FALSE(host_impl_->ScrollVerticallyByPage(
      gfx::Point(), SCROLL_BACKWARD));

  host_impl_->InnerViewportScrollLayer()->set_user_scrollable_vertical(true);
  SetNeedsRebuildPropertyTrees();
  DrawFrame();
  EXPECT_TRUE(host_impl_->ScrollVerticallyByPage(
      gfx::Point(), SCROLL_FORWARD));
  EXPECT_FLOAT_EQ(875.f,
                  ScrollDelta(host_impl_->InnerViewportScrollLayer()).y());
  EXPECT_TRUE(host_impl_->ScrollVerticallyByPage(
      gfx::Point(), SCROLL_BACKWARD));
}

TEST_F(LayerTreeHostImplTest, ScrollWithUserUnscrollableLayers) {
  LayerImpl* scroll_layer = SetupScrollAndContentsLayers(gfx::Size(200, 200));
  host_impl_->SetViewportSize(gfx::Size(100, 100));

  gfx::Size overflow_size(400, 400);
  ASSERT_EQ(1u, scroll_layer->children().size());
  LayerImpl* overflow = scroll_layer->children()[0].get();
  overflow->SetBounds(overflow_size);
  overflow->SetScrollClipLayer(scroll_layer->parent()->parent()->id());
  overflow->layer_tree_impl()
      ->property_trees()
      ->scroll_tree.UpdateScrollOffsetBaseForTesting(overflow->id(),
                                                     gfx::ScrollOffset());
  overflow->SetPosition(gfx::PointF());

  SetNeedsRebuildPropertyTrees();
  DrawFrame();
  gfx::Point scroll_position(10, 10);

  EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
            host_impl_->ScrollBegin(BeginState(scroll_position).get(),
                                    InputHandler::WHEEL)
                .thread);
  EXPECT_VECTOR_EQ(gfx::Vector2dF(), scroll_layer->CurrentScrollOffset());
  EXPECT_VECTOR_EQ(gfx::Vector2dF(), overflow->CurrentScrollOffset());

  gfx::Vector2dF scroll_delta(10, 10);
  host_impl_->ScrollBy(UpdateState(scroll_position, scroll_delta).get());
  host_impl_->ScrollEnd(EndState().get());
  EXPECT_VECTOR_EQ(gfx::Vector2dF(), scroll_layer->CurrentScrollOffset());
  EXPECT_VECTOR_EQ(gfx::Vector2dF(10, 10), overflow->CurrentScrollOffset());

  overflow->set_user_scrollable_horizontal(false);
  SetNeedsRebuildPropertyTrees();
  DrawFrame();

  EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
            host_impl_->ScrollBegin(BeginState(scroll_position).get(),
                                    InputHandler::WHEEL)
                .thread);
  EXPECT_VECTOR_EQ(gfx::Vector2dF(), scroll_layer->CurrentScrollOffset());
  EXPECT_VECTOR_EQ(gfx::Vector2dF(10, 10), overflow->CurrentScrollOffset());

  host_impl_->ScrollBy(UpdateState(scroll_position, scroll_delta).get());
  host_impl_->ScrollEnd(EndState().get());
  EXPECT_VECTOR_EQ(gfx::Vector2dF(0, 0), scroll_layer->CurrentScrollOffset());
  EXPECT_VECTOR_EQ(gfx::Vector2dF(10, 20), overflow->CurrentScrollOffset());

  overflow->set_user_scrollable_vertical(false);
  SetNeedsRebuildPropertyTrees();
  DrawFrame();

  EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
            host_impl_->ScrollBegin(BeginState(scroll_position).get(),
                                    InputHandler::WHEEL)
                .thread);
  EXPECT_VECTOR_EQ(gfx::Vector2dF(0, 0), scroll_layer->CurrentScrollOffset());
  EXPECT_VECTOR_EQ(gfx::Vector2dF(10, 20), overflow->CurrentScrollOffset());

  host_impl_->ScrollBy(UpdateState(scroll_position, scroll_delta).get());
  host_impl_->ScrollEnd(EndState().get());
  EXPECT_VECTOR_EQ(gfx::Vector2dF(10, 10), scroll_layer->CurrentScrollOffset());
  EXPECT_VECTOR_EQ(gfx::Vector2dF(10, 20), overflow->CurrentScrollOffset());
}

TEST_F(LayerTreeHostImplTest, AnimationSchedulingPendingTree) {
  EXPECT_FALSE(host_impl_->CommitToActiveTree());

  host_impl_->SetViewportSize(gfx::Size(50, 50));

  host_impl_->CreatePendingTree();
  host_impl_->pending_tree()->SetRootLayer(
      LayerImpl::Create(host_impl_->pending_tree(), 1));
  LayerImpl* root = host_impl_->pending_tree()->root_layer();
  root->SetBounds(gfx::Size(50, 50));
  root->SetForceRenderSurface(true);

  root->AddChild(LayerImpl::Create(host_impl_->pending_tree(), 2));
  LayerImpl* child = root->children()[0].get();
  child->SetBounds(gfx::Size(10, 10));
  child->draw_properties().visible_layer_rect = gfx::Rect(10, 10);
  child->SetDrawsContent(true);
  AddAnimatedTransformToLayerWithPlayer(child->id(), timeline(), 10.0, 3, 0);

  EXPECT_FALSE(did_request_next_frame_);
  EXPECT_FALSE(did_request_redraw_);
  EXPECT_FALSE(did_request_commit_);

  host_impl_->AnimatePendingTreeAfterCommit();

  // An animation exists on the pending layer. Doing
  // AnimatePendingTreeAfterCommit() requests another frame.
  // In reality, animations without has_set_start_time() == true do not need to
  // be continuously ticked on the pending tree, so it should not request
  // another animation frame here. But we currently do so blindly if any
  // animation exists.
  EXPECT_TRUE(did_request_next_frame_);
  // The pending tree with an animation does not need to draw after animating.
  EXPECT_FALSE(did_request_redraw_);
  EXPECT_FALSE(did_request_commit_);

  did_request_next_frame_ = false;
  did_request_redraw_ = false;
  did_request_commit_ = false;

  host_impl_->ActivateSyncTree();

  // When the animation activates, we should request another animation frame
  // to keep the animation moving.
  EXPECT_TRUE(did_request_next_frame_);
  // On activation we don't need to request a redraw for the animation,
  // activating will draw on its own when it's ready.
  EXPECT_FALSE(did_request_redraw_);
  EXPECT_FALSE(did_request_commit_);
}

TEST_F(LayerTreeHostImplTest, AnimationSchedulingActiveTree) {
  EXPECT_FALSE(host_impl_->CommitToActiveTree());

  host_impl_->SetViewportSize(gfx::Size(50, 50));

  host_impl_->active_tree()->SetRootLayer(
      LayerImpl::Create(host_impl_->active_tree(), 1));
  LayerImpl* root = host_impl_->active_tree()->root_layer();
  root->SetBounds(gfx::Size(50, 50));
  root->SetForceRenderSurface(true);

  root->AddChild(LayerImpl::Create(host_impl_->active_tree(), 2));
  LayerImpl* child = root->children()[0].get();
  child->SetBounds(gfx::Size(10, 10));
  child->draw_properties().visible_layer_rect = gfx::Rect(10, 10);
  child->SetDrawsContent(true);

  // Add a translate from 6,7 to 8,9.
  TransformOperations start;
  start.AppendTranslate(6.f, 7.f, 0.f);
  TransformOperations end;
  end.AppendTranslate(8.f, 9.f, 0.f);
  AddAnimatedTransformToLayerWithPlayer(child->id(), timeline(), 4.0, start,
                                        end);

  base::TimeTicks now = base::TimeTicks::Now();
  host_impl_->WillBeginImplFrame(
      CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE, now));

  // TODO(crbug.com/551134): We always request a new frame and a draw for
  // animations that are on the pending tree, but we don't need to do that
  // unless they are waiting for some future time to start.
  EXPECT_TRUE(did_request_next_frame_);
  EXPECT_TRUE(did_request_redraw_);
  EXPECT_FALSE(did_request_commit_);
  did_request_next_frame_ = false;
  did_request_redraw_ = false;
  did_request_commit_ = false;

  host_impl_->ActivateAnimations();

  // On activating an animation, we should request another frame so that we'll
  // continue ticking the animation.
  EXPECT_TRUE(did_request_next_frame_);
  EXPECT_FALSE(did_request_redraw_);
  EXPECT_FALSE(did_request_commit_);
  did_request_next_frame_ = false;
  did_request_redraw_ = false;
  did_request_commit_ = false;

  // The next frame after activating, we'll tick the animation again.
  host_impl_->Animate();

  // An animation exists on the active layer. Doing Animate() requests another
  // frame after the current one.
  EXPECT_TRUE(did_request_next_frame_);
  // The animation should cause us to draw at the frame's deadline.
  EXPECT_TRUE(did_request_redraw_);
  EXPECT_FALSE(did_request_commit_);
}

TEST_F(LayerTreeHostImplTest, AnimationSchedulingCommitToActiveTree) {
  FakeImplTaskRunnerProvider provider(nullptr);
  CreateHostImplWithTaskRunnerProvider(DefaultSettings(), CreateOutputSurface(),
                                       &provider);
  EXPECT_TRUE(host_impl_->CommitToActiveTree());

  host_impl_->SetViewportSize(gfx::Size(50, 50));

  host_impl_->active_tree()->SetRootLayer(
      LayerImpl::Create(host_impl_->active_tree(), 1));
  LayerImpl* root = host_impl_->active_tree()->root_layer();
  root->SetBounds(gfx::Size(50, 50));
  root->SetHasRenderSurface(true);

  root->AddChild(LayerImpl::Create(host_impl_->active_tree(), 2));
  LayerImpl* child = root->children()[0].get();
  child->SetBounds(gfx::Size(10, 10));
  child->draw_properties().visible_layer_rect = gfx::Rect(10, 10);
  child->SetDrawsContent(true);
  AddAnimatedTransformToLayerWithPlayer(child->id(), timeline(), 10.0, 3, 0);

  // Set up the property trees so that UpdateDrawProperties will work in
  // CommitComplete below.
  LayerImplList list;
  LayerTreeHostCommon::CalcDrawPropsImplInputsForTesting inputs(
      root, gfx::Size(50, 50), &list, 0);
  LayerTreeHostCommon::CalculateDrawProperties(&inputs);

  EXPECT_FALSE(did_request_next_frame_);
  EXPECT_FALSE(did_request_redraw_);
  EXPECT_FALSE(did_request_commit_);

  host_impl_->CommitComplete();

  // Animations on the active tree should be started and ticked, and a new frame
  // should be requested to continue ticking them.
  EXPECT_TRUE(did_request_next_frame_);
  EXPECT_TRUE(did_request_redraw_);
  EXPECT_FALSE(did_request_commit_);

  // Delete the LayerTreeHostImpl before the TaskRunnerProvider goes away.
  host_impl_ = nullptr;
}

class MissingTilesLayer : public LayerImpl {
 public:
  MissingTilesLayer(LayerTreeImpl* layer_tree_impl, int id)
      : LayerImpl(layer_tree_impl, id), has_missing_tiles_(true) {}

  void set_has_missing_tiles(bool has_missing_tiles) {
    has_missing_tiles_ = has_missing_tiles;
  }

  void AppendQuads(RenderPass* render_pass,
                   AppendQuadsData* append_quads_data) override {
    append_quads_data->num_missing_tiles += has_missing_tiles_;
  }

 private:
  bool has_missing_tiles_;
};

TEST_F(LayerTreeHostImplTest, AnimationMarksLayerNotReady) {
  host_impl_->SetViewportSize(gfx::Size(50, 50));

  host_impl_->active_tree()->SetRootLayer(
      LayerImpl::Create(host_impl_->active_tree(), 1));
  LayerImpl* root = host_impl_->active_tree()->root_layer();
  root->SetBounds(gfx::Size(50, 50));
  root->SetHasRenderSurface(true);

  root->AddChild(scoped_ptr<MissingTilesLayer>(
      new MissingTilesLayer(host_impl_->active_tree(), 2)));
  MissingTilesLayer* child =
      static_cast<MissingTilesLayer*>(root->children()[0].get());
  child->SetBounds(gfx::Size(10, 10));
  child->draw_properties().visible_layer_rect = gfx::Rect(10, 10);
  child->SetDrawsContent(true);

  EXPECT_TRUE(child->was_ever_ready_since_last_transform_animation());

  // Add a translate from 6,7 to 8,9.
  TransformOperations start;
  start.AppendTranslate(6.f, 7.f, 0.f);
  TransformOperations end;
  end.AppendTranslate(8.f, 9.f, 0.f);
  int animation_id = AddAnimatedTransformToLayerWithPlayer(
      child->id(), timeline(), 4.0, start, end);

  base::TimeTicks now = base::TimeTicks::Now();
  host_impl_->WillBeginImplFrame(
      CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE, now));

  host_impl_->ActivateAnimations();
  host_impl_->Animate();

  EXPECT_FALSE(child->was_ever_ready_since_last_transform_animation());

  host_impl_->active_tree()->property_trees()->needs_rebuild = true;
  host_impl_->active_tree()->BuildPropertyTreesForTesting();
  host_impl_->ResetRequiresHighResToDraw();

  // Child layer has an animating transform but missing tiles.
  FakeLayerTreeHostImpl::FrameData frame;
  DrawResult result = host_impl_->PrepareToDraw(&frame);
  EXPECT_EQ(DRAW_ABORTED_CHECKERBOARD_ANIMATIONS, result);
  host_impl_->DidDrawAllLayers(frame);

  child->set_has_missing_tiles(false);

  // Child layer has an animating and no missing tiles.
  result = host_impl_->PrepareToDraw(&frame);
  EXPECT_EQ(DRAW_SUCCESS, result);
  EXPECT_TRUE(child->was_ever_ready_since_last_transform_animation());
  host_impl_->DidDrawAllLayers(frame);

  // Remove the animation.
  child->set_has_missing_tiles(true);
  RemoveAnimationFromLayerWithExistingPlayer(child->id(), timeline(),
                                             animation_id);
  child->draw_properties().screen_space_transform_is_animating = false;

  // Child layer doesn't have an animation, but was never ready since the last
  // time it animated (and has missing tiles).
  result = host_impl_->PrepareToDraw(&frame);
  EXPECT_EQ(DRAW_ABORTED_CHECKERBOARD_ANIMATIONS, result);
  EXPECT_FALSE(child->was_ever_ready_since_last_transform_animation());
  host_impl_->DidDrawAllLayers(frame);

  child->set_has_missing_tiles(false);

  // Child layer doesn't have an animation and all tiles are ready.
  result = host_impl_->PrepareToDraw(&frame);
  EXPECT_EQ(DRAW_SUCCESS, result);
  EXPECT_TRUE(child->was_ever_ready_since_last_transform_animation());
  host_impl_->DidDrawAllLayers(frame);

  child->set_has_missing_tiles(true);

  // Child layer doesn't have an animation, and was ready at least once since
  // the last time it animated.
  result = host_impl_->PrepareToDraw(&frame);
  EXPECT_EQ(DRAW_SUCCESS, result);
  EXPECT_TRUE(child->was_ever_ready_since_last_transform_animation());
  host_impl_->DidDrawAllLayers(frame);
}

TEST_F(LayerTreeHostImplTest, ImplPinchZoom) {
  LayerImpl* scroll_layer = SetupScrollAndContentsLayers(gfx::Size(100, 100));
  host_impl_->SetViewportSize(gfx::Size(50, 50));
  DrawFrame();

  EXPECT_EQ(scroll_layer, host_impl_->InnerViewportScrollLayer());
  LayerImpl* container_layer = scroll_layer->scroll_clip_layer();
  EXPECT_EQ(gfx::Size(50, 50), container_layer->bounds());

  float min_page_scale = 1.f, max_page_scale = 4.f;
  float page_scale_factor = 1.f;

  // The impl-based pinch zoom should adjust the max scroll position.
  {
    host_impl_->active_tree()->PushPageScaleFromMainThread(
        page_scale_factor, min_page_scale, max_page_scale);
    host_impl_->active_tree()->SetPageScaleOnActiveTree(page_scale_factor);
    SetScrollOffsetDelta(scroll_layer, gfx::Vector2d());

    float page_scale_delta = 2.f;

    host_impl_->ScrollBegin(BeginState(gfx::Point(50, 50)).get(),
                            InputHandler::TOUCHSCREEN);
    host_impl_->PinchGestureBegin();
    host_impl_->PinchGestureUpdate(page_scale_delta, gfx::Point(50, 50));
    host_impl_->PinchGestureEnd();
    host_impl_->ScrollEnd(EndState().get());
    EXPECT_FALSE(did_request_next_frame_);
    EXPECT_TRUE(did_request_redraw_);
    EXPECT_TRUE(did_request_commit_);
    EXPECT_EQ(gfx::Size(50, 50), container_layer->bounds());

    scoped_ptr<ScrollAndScaleSet> scroll_info =
        host_impl_->ProcessScrollDeltas();
    EXPECT_EQ(scroll_info->page_scale_delta, page_scale_delta);

    EXPECT_EQ(gfx::ScrollOffset(75.0, 75.0).ToString(),
              scroll_layer->MaxScrollOffset().ToString());
  }

  // Scrolling after a pinch gesture should always be in local space.  The
  // scroll deltas have the page scale factor applied.
  {
    host_impl_->active_tree()->PushPageScaleFromMainThread(
        page_scale_factor, min_page_scale, max_page_scale);
    host_impl_->active_tree()->SetPageScaleOnActiveTree(page_scale_factor);
    SetScrollOffsetDelta(scroll_layer, gfx::Vector2d());

    float page_scale_delta = 2.f;
    host_impl_->ScrollBegin(BeginState(gfx::Point()).get(),
                            InputHandler::TOUCHSCREEN);
    host_impl_->PinchGestureBegin();
    host_impl_->PinchGestureUpdate(page_scale_delta, gfx::Point());
    host_impl_->PinchGestureEnd();
    host_impl_->ScrollEnd(EndState().get());

    gfx::Vector2d scroll_delta(0, 10);
    EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
              host_impl_->ScrollBegin(BeginState(gfx::Point(5, 5)).get(),
                                      InputHandler::WHEEL)
                  .thread);
    host_impl_->ScrollBy(UpdateState(gfx::Point(), scroll_delta).get());
    host_impl_->ScrollEnd(EndState().get());

    scoped_ptr<ScrollAndScaleSet> scroll_info =
        host_impl_->ProcessScrollDeltas();
    EXPECT_TRUE(ScrollInfoContains(
        *scroll_info.get(), scroll_layer->id(),
        gfx::Vector2d(0, scroll_delta.y() / page_scale_delta)));
  }
}

TEST_F(LayerTreeHostImplTest, ViewportScrollOrder) {
  LayerTreeSettings settings = DefaultSettings();
  CreateHostImpl(settings,
                 CreateOutputSurface());
  host_impl_->active_tree()->PushPageScaleFromMainThread(1.f, 0.25f, 4.f);

  const gfx::Size content_size(1000, 1000);
  const gfx::Size viewport_size(500, 500);
  CreateBasicVirtualViewportLayers(viewport_size, content_size);

  LayerImpl* outer_scroll_layer = host_impl_->OuterViewportScrollLayer();
  outer_scroll_layer->SetDrawsContent(true);
  LayerImpl* inner_scroll_layer = host_impl_->InnerViewportScrollLayer();
  inner_scroll_layer->SetDrawsContent(true);

  EXPECT_VECTOR_EQ(
      gfx::Vector2dF(500, 500),
      outer_scroll_layer->MaxScrollOffset());

  RebuildPropertyTrees();
  host_impl_->ScrollBegin(BeginState(gfx::Point(250, 250)).get(),
                          InputHandler::TOUCHSCREEN);
  host_impl_->PinchGestureBegin();
  host_impl_->PinchGestureUpdate(2.f, gfx::Point(0, 0));
  host_impl_->PinchGestureEnd();
  host_impl_->ScrollEnd(EndState().get());

  // Sanity check - we're zoomed in, starting from the origin.
  EXPECT_VECTOR_EQ(
      gfx::Vector2dF(0, 0),
      outer_scroll_layer->CurrentScrollOffset());
  EXPECT_VECTOR_EQ(
      gfx::Vector2dF(0, 0),
      inner_scroll_layer->CurrentScrollOffset());

  // Scroll down - only the inner viewport should scroll.
  host_impl_->ScrollBegin(BeginState(gfx::Point(0, 0)).get(),
                          InputHandler::TOUCHSCREEN);
  host_impl_->ScrollBy(
      UpdateState(gfx::Point(0, 0), gfx::Vector2dF(100.f, 100.f)).get());
  host_impl_->ScrollEnd(EndState().get());

  EXPECT_VECTOR_EQ(
      gfx::Vector2dF(50, 50),
      inner_scroll_layer->CurrentScrollOffset());
  EXPECT_VECTOR_EQ(
      gfx::Vector2dF(0, 0),
      outer_scroll_layer->CurrentScrollOffset());

  // Scroll down - outer viewport should start scrolling after the inner is at
  // its maximum.
  host_impl_->ScrollBegin(BeginState(gfx::Point(0, 0)).get(),
                          InputHandler::TOUCHSCREEN);
  host_impl_->ScrollBy(
      UpdateState(gfx::Point(0, 0), gfx::Vector2dF(1000.f, 1000.f)).get());
  host_impl_->ScrollEnd(EndState().get());

  EXPECT_VECTOR_EQ(
      gfx::Vector2dF(250, 250),
      inner_scroll_layer->CurrentScrollOffset());
  EXPECT_VECTOR_EQ(
      gfx::Vector2dF(300, 300),
      outer_scroll_layer->CurrentScrollOffset());
}

// Make sure scrolls smaller than a unit applied to the viewport don't get
// dropped. crbug.com/539334.
TEST_F(LayerTreeHostImplTest, ScrollViewportWithFractionalAmounts) {
  LayerTreeSettings settings = DefaultSettings();
  CreateHostImpl(settings, CreateOutputSurface());
  host_impl_->active_tree()->PushPageScaleFromMainThread(1.f, 1.f, 2.f);

  const gfx::Size content_size(1000, 1000);
  const gfx::Size viewport_size(500, 500);
  CreateBasicVirtualViewportLayers(viewport_size, content_size);

  LayerImpl* outer_scroll_layer = host_impl_->OuterViewportScrollLayer();
  outer_scroll_layer->SetDrawsContent(true);
  LayerImpl* inner_scroll_layer = host_impl_->InnerViewportScrollLayer();
  inner_scroll_layer->SetDrawsContent(true);

  // Sanity checks.
  EXPECT_VECTOR_EQ(
      gfx::Vector2dF(500, 500),
      outer_scroll_layer->MaxScrollOffset());
  EXPECT_VECTOR_EQ(gfx::Vector2dF(), outer_scroll_layer->CurrentScrollOffset());
  EXPECT_VECTOR_EQ(gfx::Vector2dF(), inner_scroll_layer->CurrentScrollOffset());

  RebuildPropertyTrees();

  // Scroll only the layout viewport.
  host_impl_->ScrollBegin(BeginState(gfx::Point(250, 250)).get(),
                          InputHandler::TOUCHSCREEN);
  host_impl_->ScrollBy(
      UpdateState(gfx::Point(250, 250), gfx::Vector2dF(0.125f, 0.125f)).get());
  EXPECT_VECTOR2DF_EQ(
      gfx::Vector2dF(0.125f, 0.125f),
      outer_scroll_layer->CurrentScrollOffset());
  EXPECT_VECTOR2DF_EQ(
      gfx::Vector2dF(0, 0),
      inner_scroll_layer->CurrentScrollOffset());
  host_impl_->ScrollEnd(EndState().get());

  host_impl_->active_tree()->PushPageScaleFromMainThread(2.f, 1.f, 2.f);

  // Now that we zoomed in, the scroll should be applied to the inner viewport.
  host_impl_->ScrollBegin(BeginState(gfx::Point(250, 250)).get(),
                          InputHandler::TOUCHSCREEN);
  host_impl_->ScrollBy(
      UpdateState(gfx::Point(250, 250), gfx::Vector2dF(0.5f, 0.5f)).get());
  EXPECT_VECTOR2DF_EQ(
      gfx::Vector2dF(0.125f, 0.125f),
      outer_scroll_layer->CurrentScrollOffset());
  EXPECT_VECTOR2DF_EQ(
      gfx::Vector2dF(0.25f, 0.25f),
      inner_scroll_layer->CurrentScrollOffset());
  host_impl_->ScrollEnd(EndState().get());
}

// Tests that scrolls during a pinch gesture (i.e. "two-finger" scrolls) work
// as expected. That is, scrolling during a pinch should bubble from the inner
// to the outer viewport.
TEST_F(LayerTreeHostImplTest, ScrollDuringPinchGesture) {
  LayerTreeSettings settings = DefaultSettings();
  CreateHostImpl(settings,
                 CreateOutputSurface());
  host_impl_->active_tree()->PushPageScaleFromMainThread(1.f, 1.f, 2.f);

  const gfx::Size content_size(1000, 1000);
  const gfx::Size viewport_size(500, 500);
  CreateBasicVirtualViewportLayers(viewport_size, content_size);

  LayerImpl* outer_scroll_layer = host_impl_->OuterViewportScrollLayer();
  outer_scroll_layer->SetDrawsContent(true);
  LayerImpl* inner_scroll_layer = host_impl_->InnerViewportScrollLayer();
  inner_scroll_layer->SetDrawsContent(true);

  EXPECT_VECTOR_EQ(
      gfx::Vector2dF(500, 500),
      outer_scroll_layer->MaxScrollOffset());

  RebuildPropertyTrees();
  host_impl_->ScrollBegin(BeginState(gfx::Point(250, 250)).get(),
                          InputHandler::TOUCHSCREEN);
  host_impl_->PinchGestureBegin();

  host_impl_->PinchGestureUpdate(2, gfx::Point(250, 250));
  EXPECT_VECTOR_EQ(
      gfx::Vector2dF(0, 0),
      outer_scroll_layer->CurrentScrollOffset());
  EXPECT_VECTOR_EQ(
      gfx::Vector2dF(125, 125),
      inner_scroll_layer->CurrentScrollOffset());

  // Needed so that the pinch is accounted for in draw properties.
  DrawFrame();

  host_impl_->ScrollBy(
      UpdateState(gfx::Point(250, 250), gfx::Vector2dF(10.f, 10.f)).get());
  EXPECT_VECTOR_EQ(
      gfx::Vector2dF(0, 0),
      outer_scroll_layer->CurrentScrollOffset());
  EXPECT_VECTOR_EQ(
      gfx::Vector2dF(130, 130),
      inner_scroll_layer->CurrentScrollOffset());

  DrawFrame();

  host_impl_->ScrollBy(
      UpdateState(gfx::Point(250, 250), gfx::Vector2dF(400.f, 400.f)).get());
  EXPECT_VECTOR_EQ(
      gfx::Vector2dF(80, 80),
      outer_scroll_layer->CurrentScrollOffset());
  EXPECT_VECTOR_EQ(
      gfx::Vector2dF(250, 250),
      inner_scroll_layer->CurrentScrollOffset());

  host_impl_->PinchGestureEnd();
  host_impl_->ScrollEnd(EndState().get());
}

// Tests the "snapping" of pinch-zoom gestures to the screen edge. That is, when
// a pinch zoom is anchored within a certain margin of the screen edge, we
// should assume the user means to scroll into the edge of the screen.
TEST_F(LayerTreeHostImplTest, PinchZoomSnapsToScreenEdge) {
  LayerTreeSettings settings = DefaultSettings();
  CreateHostImpl(settings,
                 CreateOutputSurface());
  host_impl_->active_tree()->PushPageScaleFromMainThread(1.f, 1.f, 2.f);

  const gfx::Size content_size(1000, 1000);
  const gfx::Size viewport_size(500, 500);
  CreateBasicVirtualViewportLayers(viewport_size, content_size);

  int offsetFromEdge = Viewport::kPinchZoomSnapMarginDips - 5;
  gfx::Point anchor(viewport_size.width() - offsetFromEdge,
                    viewport_size.height() - offsetFromEdge);

  // Pinch in within the margins. The scroll should stay exactly locked to the
  // bottom and right.
  RebuildPropertyTrees();
  host_impl_->ScrollBegin(BeginState(anchor).get(), InputHandler::TOUCHSCREEN);
  host_impl_->PinchGestureBegin();
  host_impl_->PinchGestureUpdate(2, anchor);
  host_impl_->PinchGestureEnd();
  host_impl_->ScrollEnd(EndState().get());

  EXPECT_VECTOR_EQ(
      gfx::Vector2dF(250, 250),
      host_impl_->InnerViewportScrollLayer()->CurrentScrollOffset());

  // Reset.
  host_impl_->active_tree()->SetPageScaleOnActiveTree(1.f);
  SetScrollOffsetDelta(host_impl_->InnerViewportScrollLayer(), gfx::Vector2d());
  SetScrollOffsetDelta(host_impl_->OuterViewportScrollLayer(), gfx::Vector2d());

  // Pinch in within the margins. The scroll should stay exactly locked to the
  // top and left.
  anchor = gfx::Point(offsetFromEdge, offsetFromEdge);
  host_impl_->ScrollBegin(BeginState(anchor).get(), InputHandler::TOUCHSCREEN);
  host_impl_->PinchGestureBegin();
  host_impl_->PinchGestureUpdate(2, anchor);
  host_impl_->PinchGestureEnd();
  host_impl_->ScrollEnd(EndState().get());

  EXPECT_VECTOR_EQ(
      gfx::Vector2dF(0, 0),
      host_impl_->InnerViewportScrollLayer()->CurrentScrollOffset());

  // Reset.
  host_impl_->active_tree()->SetPageScaleOnActiveTree(1.f);
  SetScrollOffsetDelta(host_impl_->InnerViewportScrollLayer(), gfx::Vector2d());
  SetScrollOffsetDelta(host_impl_->OuterViewportScrollLayer(), gfx::Vector2d());

  // Pinch in just outside the margin. There should be no snapping.
  offsetFromEdge = Viewport::kPinchZoomSnapMarginDips;
  anchor = gfx::Point(offsetFromEdge, offsetFromEdge);
  host_impl_->ScrollBegin(BeginState(anchor).get(), InputHandler::TOUCHSCREEN);
  host_impl_->PinchGestureBegin();
  host_impl_->PinchGestureUpdate(2, anchor);
  host_impl_->PinchGestureEnd();
  host_impl_->ScrollEnd(EndState().get());

  EXPECT_VECTOR_EQ(
      gfx::Vector2dF(50, 50),
      host_impl_->InnerViewportScrollLayer()->CurrentScrollOffset());

  // Reset.
  host_impl_->active_tree()->SetPageScaleOnActiveTree(1.f);
  SetScrollOffsetDelta(host_impl_->InnerViewportScrollLayer(), gfx::Vector2d());
  SetScrollOffsetDelta(host_impl_->OuterViewportScrollLayer(), gfx::Vector2d());

  // Pinch in just outside the margin. There should be no snapping.
  offsetFromEdge = Viewport::kPinchZoomSnapMarginDips;
  anchor = gfx::Point(viewport_size.width() - offsetFromEdge,
                      viewport_size.height() - offsetFromEdge);
  host_impl_->ScrollBegin(BeginState(anchor).get(), InputHandler::TOUCHSCREEN);
  host_impl_->PinchGestureBegin();
  host_impl_->PinchGestureUpdate(2, anchor);
  host_impl_->PinchGestureEnd();
  host_impl_->ScrollEnd(EndState().get());

  EXPECT_VECTOR_EQ(
      gfx::Vector2dF(200, 200),
      host_impl_->InnerViewportScrollLayer()->CurrentScrollOffset());
}

TEST_F(LayerTreeHostImplTest, ImplPinchZoomWheelBubbleBetweenViewports) {
  const gfx::Size content_size(200, 200);
  const gfx::Size viewport_size(100, 100);
  CreateBasicVirtualViewportLayers(viewport_size, content_size);

  LayerImpl* outer_scroll_layer = host_impl_->OuterViewportScrollLayer();
  LayerImpl* inner_scroll_layer = host_impl_->InnerViewportScrollLayer();

  // Zoom into the page by a 2X factor
  float min_page_scale = 1.f, max_page_scale = 4.f;
  float page_scale_factor = 2.f;
  RebuildPropertyTrees();
  host_impl_->active_tree()->PushPageScaleFromMainThread(
      page_scale_factor, min_page_scale, max_page_scale);
  host_impl_->active_tree()->SetPageScaleOnActiveTree(page_scale_factor);

  // Scroll by a small amount, there should be no bubbling to the outer
  // viewport.
  host_impl_->ScrollBegin(BeginState(gfx::Point(0, 0)).get(),
                          InputHandler::WHEEL);
  host_impl_->ScrollBy(
      UpdateState(gfx::Point(0, 0), gfx::Vector2dF(10.f, 20.f)).get());
  host_impl_->ScrollEnd(EndState().get());

  EXPECT_VECTOR_EQ(
      gfx::Vector2dF(5, 10),
      inner_scroll_layer->CurrentScrollOffset());
  EXPECT_VECTOR_EQ(
      gfx::Vector2dF(),
      outer_scroll_layer->CurrentScrollOffset());

  // Scroll by the inner viewport's max scroll extent, the remainder
  // should bubble up to the outer viewport.
  host_impl_->ScrollBegin(BeginState(gfx::Point(0, 0)).get(),
                          InputHandler::WHEEL);
  host_impl_->ScrollBy(
      UpdateState(gfx::Point(0, 0), gfx::Vector2dF(100.f, 100.f)).get());
  host_impl_->ScrollEnd(EndState().get());

  EXPECT_VECTOR_EQ(
      gfx::Vector2dF(50, 50),
      inner_scroll_layer->CurrentScrollOffset());
  EXPECT_VECTOR_EQ(
      gfx::Vector2dF(5, 10),
      outer_scroll_layer->CurrentScrollOffset());

  // Scroll by the outer viewport's max scroll extent, it should all go to the
  // outer viewport.
  host_impl_->ScrollBegin(BeginState(gfx::Point(0, 0)).get(),
                          InputHandler::WHEEL);
  host_impl_->ScrollBy(
      UpdateState(gfx::Point(0, 0), gfx::Vector2dF(190.f, 180.f)).get());
  host_impl_->ScrollEnd(EndState().get());

  EXPECT_VECTOR_EQ(
      gfx::Vector2dF(100, 100),
      outer_scroll_layer->CurrentScrollOffset());
  EXPECT_VECTOR_EQ(
      gfx::Vector2dF(50, 50),
      inner_scroll_layer->CurrentScrollOffset());
}

TEST_F(LayerTreeHostImplTest, ScrollWithSwapPromises) {
  ui::LatencyInfo latency_info;
  latency_info.AddLatencyNumber(ui::INPUT_EVENT_LATENCY_BEGIN_RWH_COMPONENT, 0,
                                1234);
  scoped_ptr<SwapPromise> swap_promise(
      new LatencyInfoSwapPromise(latency_info));

  SetupScrollAndContentsLayers(gfx::Size(100, 100));
  EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
            host_impl_
                ->ScrollBegin(BeginState(gfx::Point()).get(),
                              InputHandler::TOUCHSCREEN)
                .thread);
  host_impl_->ScrollBy(UpdateState(gfx::Point(), gfx::Vector2d(0, 10)).get());
  host_impl_->QueueSwapPromiseForMainThreadScrollUpdate(
      std::move(swap_promise));
  host_impl_->ScrollEnd(EndState().get());

  scoped_ptr<ScrollAndScaleSet> scroll_info = host_impl_->ProcessScrollDeltas();
  EXPECT_EQ(1u, scroll_info->swap_promises.size());
  EXPECT_EQ(latency_info.trace_id(), scroll_info->swap_promises[0]->TraceId());
}

// Test that scrolls targeting a layer with a non-null scroll_parent() don't
// bubble up.
TEST_F(LayerTreeHostImplTest, ScrollDoesntBubble) {
  LayerImpl* viewport_scroll =
      SetupScrollAndContentsLayers(gfx::Size(100, 100));
  host_impl_->SetViewportSize(gfx::Size(50, 50));

  // Set up two scrolling children of the root, one of which is a scroll parent
  // to the other. Scrolls shouldn't bubbling from the child.
  LayerImpl *parent;
  LayerImpl *child;
  LayerImpl *child_clip;

  scoped_ptr<LayerImpl> scroll_parent_clip =
      LayerImpl::Create(host_impl_->active_tree(), 6);
  scoped_ptr<LayerImpl> scroll_parent = CreateScrollableLayer(
      7, gfx::Size(10, 10), scroll_parent_clip.get());
  parent = scroll_parent.get();
  scroll_parent_clip->AddChild(std::move(scroll_parent));

  viewport_scroll->AddChild(std::move(scroll_parent_clip));

  scoped_ptr<LayerImpl> scroll_child_clip =
      LayerImpl::Create(host_impl_->active_tree(), 8);
  scoped_ptr<LayerImpl> scroll_child = CreateScrollableLayer(
      9, gfx::Size(10, 10), scroll_child_clip.get());
  child = scroll_child.get();
  scroll_child->SetPosition(gfx::PointF(20.f, 20.f));
  scroll_child_clip->AddChild(std::move(scroll_child));

  child_clip = scroll_child_clip.get();
  viewport_scroll->AddChild(std::move(scroll_child_clip));

  child_clip->SetScrollParent(parent);
  scoped_ptr<std::set<LayerImpl*>> scroll_children(new std::set<LayerImpl*>);
  scroll_children->insert(child_clip);
  parent->SetScrollChildren(scroll_children.release());

  SetNeedsRebuildPropertyTrees();
  DrawFrame();

  {
    host_impl_->ScrollBegin(BeginState(gfx::Point(21, 21)).get(),
                            InputHandler::TOUCHSCREEN);
    host_impl_->ScrollBy(
        UpdateState(gfx::Point(21, 21), gfx::Vector2d(5, 5)).get());
    host_impl_->ScrollBy(
        UpdateState(gfx::Point(21, 21), gfx::Vector2d(100, 100)).get());
    host_impl_->ScrollEnd(EndState().get());

    // The child should be fully scrolled by the first ScrollBy.
    EXPECT_VECTOR_EQ(gfx::Vector2dF(5, 5), child->CurrentScrollOffset());

    // The scroll_parent shouldn't receive the second ScrollBy.
    EXPECT_VECTOR_EQ(gfx::Vector2dF(0, 0), parent->CurrentScrollOffset());

    // The viewport shouldn't have been scrolled at all.
    EXPECT_VECTOR_EQ(
        gfx::Vector2dF(0, 0),
        host_impl_->InnerViewportScrollLayer()->CurrentScrollOffset());
    EXPECT_VECTOR_EQ(
        gfx::Vector2dF(0, 0),
        host_impl_->OuterViewportScrollLayer()->CurrentScrollOffset());
  }

  {
    host_impl_->ScrollBegin(BeginState(gfx::Point(21, 21)).get(),
                            InputHandler::TOUCHSCREEN);
    host_impl_->ScrollBy(
        UpdateState(gfx::Point(21, 21), gfx::Vector2d(3, 4)).get());
    host_impl_->ScrollBy(
        UpdateState(gfx::Point(21, 21), gfx::Vector2d(2, 1)).get());
    host_impl_->ScrollBy(
        UpdateState(gfx::Point(21, 21), gfx::Vector2d(2, 1)).get());
    host_impl_->ScrollBy(
        UpdateState(gfx::Point(21, 21), gfx::Vector2d(2, 1)).get());
    host_impl_->ScrollEnd(EndState().get());

    // The ScrollBy's should scroll the parent to its extent.
    EXPECT_VECTOR_EQ(gfx::Vector2dF(5, 5), parent->CurrentScrollOffset());

    // The viewport shouldn't receive any scroll delta.
    EXPECT_VECTOR_EQ(
        gfx::Vector2dF(0, 0),
        host_impl_->InnerViewportScrollLayer()->CurrentScrollOffset());
    EXPECT_VECTOR_EQ(
        gfx::Vector2dF(0, 0),
        host_impl_->OuterViewportScrollLayer()->CurrentScrollOffset());
  }
}


TEST_F(LayerTreeHostImplTest, PinchGesture) {
  SetupScrollAndContentsLayers(gfx::Size(100, 100));
  host_impl_->SetViewportSize(gfx::Size(50, 50));
  DrawFrame();

  LayerImpl* scroll_layer = host_impl_->InnerViewportScrollLayer();
  DCHECK(scroll_layer);

  float min_page_scale = 1.f;
  float max_page_scale = 4.f;

  // Basic pinch zoom in gesture
  {
    host_impl_->active_tree()->PushPageScaleFromMainThread(1.f, min_page_scale,
                                                           max_page_scale);
    SetScrollOffsetDelta(scroll_layer, gfx::Vector2d());

    float page_scale_delta = 2.f;
    host_impl_->ScrollBegin(BeginState(gfx::Point(50, 50)).get(),
                            InputHandler::TOUCHSCREEN);
    host_impl_->PinchGestureBegin();
    host_impl_->PinchGestureUpdate(page_scale_delta, gfx::Point(50, 50));
    host_impl_->PinchGestureEnd();
    host_impl_->ScrollEnd(EndState().get());
    EXPECT_FALSE(did_request_next_frame_);
    EXPECT_TRUE(did_request_redraw_);
    EXPECT_TRUE(did_request_commit_);

    scoped_ptr<ScrollAndScaleSet> scroll_info =
        host_impl_->ProcessScrollDeltas();
    EXPECT_EQ(scroll_info->page_scale_delta, page_scale_delta);
  }

  // Zoom-in clamping
  {
    host_impl_->active_tree()->PushPageScaleFromMainThread(1.f, min_page_scale,
                                                           max_page_scale);
    SetScrollOffsetDelta(scroll_layer, gfx::Vector2d());
    float page_scale_delta = 10.f;

    host_impl_->ScrollBegin(BeginState(gfx::Point(50, 50)).get(),
                            InputHandler::TOUCHSCREEN);
    host_impl_->PinchGestureBegin();
    host_impl_->PinchGestureUpdate(page_scale_delta, gfx::Point(50, 50));
    host_impl_->PinchGestureEnd();
    host_impl_->ScrollEnd(EndState().get());

    scoped_ptr<ScrollAndScaleSet> scroll_info =
        host_impl_->ProcessScrollDeltas();
    EXPECT_EQ(scroll_info->page_scale_delta, max_page_scale);
  }

  // Zoom-out clamping
  {
    host_impl_->active_tree()->PushPageScaleFromMainThread(1.f, min_page_scale,
                                                           max_page_scale);
    SetScrollOffsetDelta(scroll_layer, gfx::Vector2d());
    scroll_layer->layer_tree_impl()
        ->property_trees()
        ->scroll_tree.CollectScrollDeltasForTesting();
    scroll_layer->layer_tree_impl()
        ->property_trees()
        ->scroll_tree.UpdateScrollOffsetBaseForTesting(
            scroll_layer->id(), gfx::ScrollOffset(50, 50));

    float page_scale_delta = 0.1f;
    host_impl_->ScrollBegin(BeginState(gfx::Point()).get(),
                            InputHandler::TOUCHSCREEN);
    host_impl_->PinchGestureBegin();
    host_impl_->PinchGestureUpdate(page_scale_delta, gfx::Point());
    host_impl_->PinchGestureEnd();
    host_impl_->ScrollEnd(EndState().get());

    scoped_ptr<ScrollAndScaleSet> scroll_info =
        host_impl_->ProcessScrollDeltas();
    EXPECT_EQ(scroll_info->page_scale_delta, min_page_scale);

    EXPECT_TRUE(scroll_info->scrolls.empty());
  }

  // Two-finger panning should not happen based on pinch events only
  {
    host_impl_->active_tree()->PushPageScaleFromMainThread(1.f, min_page_scale,
                                                           max_page_scale);
    SetScrollOffsetDelta(scroll_layer, gfx::Vector2d());
    scroll_layer->layer_tree_impl()
        ->property_trees()
        ->scroll_tree.CollectScrollDeltasForTesting();
    scroll_layer->layer_tree_impl()
        ->property_trees()
        ->scroll_tree.UpdateScrollOffsetBaseForTesting(
            scroll_layer->id(), gfx::ScrollOffset(20, 20));

    float page_scale_delta = 1.f;
    host_impl_->ScrollBegin(BeginState(gfx::Point(10, 10)).get(),
                            InputHandler::TOUCHSCREEN);
    host_impl_->PinchGestureBegin();
    host_impl_->PinchGestureUpdate(page_scale_delta, gfx::Point(10, 10));
    host_impl_->PinchGestureUpdate(page_scale_delta, gfx::Point(20, 20));
    host_impl_->PinchGestureEnd();
    host_impl_->ScrollEnd(EndState().get());

    scoped_ptr<ScrollAndScaleSet> scroll_info =
        host_impl_->ProcessScrollDeltas();
    EXPECT_EQ(scroll_info->page_scale_delta, page_scale_delta);
    EXPECT_TRUE(scroll_info->scrolls.empty());
  }

  // Two-finger panning should work with interleaved scroll events
  {
    host_impl_->active_tree()->PushPageScaleFromMainThread(1.f, min_page_scale,
                                                           max_page_scale);
    SetScrollOffsetDelta(scroll_layer, gfx::Vector2d());
    scroll_layer->layer_tree_impl()
        ->property_trees()
        ->scroll_tree.CollectScrollDeltasForTesting();
    scroll_layer->layer_tree_impl()
        ->property_trees()
        ->scroll_tree.UpdateScrollOffsetBaseForTesting(
            scroll_layer->id(), gfx::ScrollOffset(20, 20));

    float page_scale_delta = 1.f;
    host_impl_->ScrollBegin(BeginState(gfx::Point(10, 10)).get(),
                            InputHandler::TOUCHSCREEN);
    host_impl_->PinchGestureBegin();
    host_impl_->PinchGestureUpdate(page_scale_delta, gfx::Point(10, 10));
    host_impl_->ScrollBy(
        UpdateState(gfx::Point(10, 10), gfx::Vector2d(-10, -10)).get());
    host_impl_->PinchGestureUpdate(page_scale_delta, gfx::Point(20, 20));
    host_impl_->PinchGestureEnd();
    host_impl_->ScrollEnd(EndState().get());

    scoped_ptr<ScrollAndScaleSet> scroll_info =
        host_impl_->ProcessScrollDeltas();
    EXPECT_EQ(scroll_info->page_scale_delta, page_scale_delta);
    EXPECT_TRUE(ScrollInfoContains(*scroll_info, scroll_layer->id(),
                                   gfx::Vector2d(-10, -10)));
  }

  // Two-finger panning should work when starting fully zoomed out.
  {
    host_impl_->active_tree()->PushPageScaleFromMainThread(0.5f, 0.5f, 4.f);
    SetScrollOffsetDelta(scroll_layer, gfx::Vector2d());
    scroll_layer->layer_tree_impl()
        ->property_trees()
        ->scroll_tree.CollectScrollDeltasForTesting();
    scroll_layer->layer_tree_impl()
        ->property_trees()
        ->scroll_tree.UpdateScrollOffsetBaseForTesting(scroll_layer->id(),
                                                       gfx::ScrollOffset(0, 0));

    host_impl_->ScrollBegin(BeginState(gfx::Point(0, 0)).get(),
                            InputHandler::TOUCHSCREEN);
    host_impl_->PinchGestureBegin();
    host_impl_->PinchGestureUpdate(2.f, gfx::Point(0, 0));
    host_impl_->PinchGestureUpdate(1.f, gfx::Point(0, 0));

    // Needed so layer transform includes page scale.
    DrawFrame();

    host_impl_->ScrollBy(
        UpdateState(gfx::Point(0, 0), gfx::Vector2d(10, 10)).get());
    host_impl_->PinchGestureUpdate(1.f, gfx::Point(10, 10));
    host_impl_->PinchGestureEnd();
    host_impl_->ScrollEnd(EndState().get());

    scoped_ptr<ScrollAndScaleSet> scroll_info =
        host_impl_->ProcessScrollDeltas();
    EXPECT_EQ(scroll_info->page_scale_delta, 2.f);
    EXPECT_TRUE(ScrollInfoContains(*scroll_info, scroll_layer->id(),
                                   gfx::Vector2d(10, 10)));
  }
}

TEST_F(LayerTreeHostImplTest, PageScaleAnimation) {
  SetupScrollAndContentsLayers(gfx::Size(100, 100));
  host_impl_->SetViewportSize(gfx::Size(50, 50));
  DrawFrame();

  LayerImpl* scroll_layer = host_impl_->InnerViewportScrollLayer();
  DCHECK(scroll_layer);

  float min_page_scale = 0.5f;
  float max_page_scale = 4.f;
  base::TimeTicks start_time = base::TimeTicks() +
                               base::TimeDelta::FromSeconds(1);
  base::TimeDelta duration = base::TimeDelta::FromMilliseconds(100);
  base::TimeTicks halfway_through_animation = start_time + duration / 2;
  base::TimeTicks end_time = start_time + duration;

  BeginFrameArgs begin_frame_args =
      CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE);

  // Non-anchor zoom-in
  {
    host_impl_->active_tree()->PushPageScaleFromMainThread(1.f, min_page_scale,
                                                           max_page_scale);
    scroll_layer->layer_tree_impl()
        ->property_trees()
        ->scroll_tree.UpdateScrollOffsetBaseForTesting(
            scroll_layer->id(), gfx::ScrollOffset(50, 50));

    did_request_redraw_ = false;
    did_request_next_frame_ = false;
    host_impl_->active_tree()->SetPendingPageScaleAnimation(
        scoped_ptr<PendingPageScaleAnimation>(new PendingPageScaleAnimation(
            gfx::Vector2d(),
            false,
            2.f,
            duration)));
    host_impl_->ActivateSyncTree();
    EXPECT_FALSE(did_request_redraw_);
    EXPECT_TRUE(did_request_next_frame_);

    did_request_redraw_ = false;
    did_request_next_frame_ = false;
    begin_frame_args.frame_time = start_time;
    host_impl_->WillBeginImplFrame(begin_frame_args);
    host_impl_->Animate();
    EXPECT_TRUE(did_request_redraw_);
    EXPECT_TRUE(did_request_next_frame_);
    host_impl_->DidFinishImplFrame();

    did_request_redraw_ = false;
    did_request_next_frame_ = false;
    begin_frame_args.frame_time = halfway_through_animation;
    host_impl_->WillBeginImplFrame(begin_frame_args);
    host_impl_->Animate();
    EXPECT_TRUE(did_request_redraw_);
    EXPECT_TRUE(did_request_next_frame_);
    host_impl_->DidFinishImplFrame();

    did_request_redraw_ = false;
    did_request_next_frame_ = false;
    did_request_commit_ = false;
    begin_frame_args.frame_time = end_time;
    host_impl_->WillBeginImplFrame(begin_frame_args);
    host_impl_->Animate();
    EXPECT_TRUE(did_request_commit_);
    EXPECT_FALSE(did_request_next_frame_);
    host_impl_->DidFinishImplFrame();

    scoped_ptr<ScrollAndScaleSet> scroll_info =
        host_impl_->ProcessScrollDeltas();
    EXPECT_EQ(scroll_info->page_scale_delta, 2);
    EXPECT_TRUE(ScrollInfoContains(*scroll_info, scroll_layer->id(),
                                   gfx::Vector2d(-50, -50)));
  }

  start_time += base::TimeDelta::FromSeconds(10);
  halfway_through_animation += base::TimeDelta::FromSeconds(10);
  end_time += base::TimeDelta::FromSeconds(10);

  // Anchor zoom-out
  {
    host_impl_->active_tree()->PushPageScaleFromMainThread(1.f, min_page_scale,
                                                           max_page_scale);
    scroll_layer->layer_tree_impl()
        ->property_trees()
        ->scroll_tree.UpdateScrollOffsetBaseForTesting(
            scroll_layer->id(), gfx::ScrollOffset(50, 50));

    did_request_redraw_ = false;
    did_request_next_frame_ = false;
    host_impl_->active_tree()->SetPendingPageScaleAnimation(
        scoped_ptr<PendingPageScaleAnimation> (new PendingPageScaleAnimation(
            gfx::Vector2d(25, 25),
            true,
            min_page_scale,
            duration)));
    host_impl_->ActivateSyncTree();
    EXPECT_FALSE(did_request_redraw_);
    EXPECT_TRUE(did_request_next_frame_);

    did_request_redraw_ = false;
    did_request_next_frame_ = false;
    begin_frame_args.frame_time = start_time;
    host_impl_->WillBeginImplFrame(begin_frame_args);
    host_impl_->Animate();
    EXPECT_TRUE(did_request_redraw_);
    EXPECT_TRUE(did_request_next_frame_);
    host_impl_->DidFinishImplFrame();

    did_request_redraw_ = false;
    did_request_commit_ = false;
    did_request_next_frame_ = false;
    begin_frame_args.frame_time = end_time;
    host_impl_->WillBeginImplFrame(begin_frame_args);
    host_impl_->Animate();
    EXPECT_TRUE(did_request_redraw_);
    EXPECT_FALSE(did_request_next_frame_);
    EXPECT_TRUE(did_request_commit_);
    host_impl_->DidFinishImplFrame();

    scoped_ptr<ScrollAndScaleSet> scroll_info =
        host_impl_->ProcessScrollDeltas();
    EXPECT_EQ(scroll_info->page_scale_delta, min_page_scale);
    // Pushed to (0,0) via clamping against contents layer size.
    EXPECT_TRUE(ScrollInfoContains(*scroll_info, scroll_layer->id(),
                                   gfx::Vector2d(-50, -50)));
  }
}

TEST_F(LayerTreeHostImplTest, PageScaleAnimationNoOp) {
  SetupScrollAndContentsLayers(gfx::Size(100, 100));
  host_impl_->SetViewportSize(gfx::Size(50, 50));
  DrawFrame();

  LayerImpl* scroll_layer = host_impl_->InnerViewportScrollLayer();
  DCHECK(scroll_layer);

  float min_page_scale = 0.5f;
  float max_page_scale = 4.f;
  base::TimeTicks start_time = base::TimeTicks() +
                               base::TimeDelta::FromSeconds(1);
  base::TimeDelta duration = base::TimeDelta::FromMilliseconds(100);
  base::TimeTicks halfway_through_animation = start_time + duration / 2;
  base::TimeTicks end_time = start_time + duration;

  BeginFrameArgs begin_frame_args =
      CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE);

  // Anchor zoom with unchanged page scale should not change scroll or scale.
  {
    host_impl_->active_tree()->PushPageScaleFromMainThread(1.f, min_page_scale,
                                                           max_page_scale);
    scroll_layer->layer_tree_impl()
        ->property_trees()
        ->scroll_tree.UpdateScrollOffsetBaseForTesting(
            scroll_layer->id(), gfx::ScrollOffset(50, 50));

    host_impl_->active_tree()->SetPendingPageScaleAnimation(
        scoped_ptr<PendingPageScaleAnimation>(new PendingPageScaleAnimation(
            gfx::Vector2d(),
            true,
            1.f,
            duration)));
    host_impl_->ActivateSyncTree();
    begin_frame_args.frame_time = start_time;
    host_impl_->WillBeginImplFrame(begin_frame_args);
    host_impl_->Animate();
    host_impl_->DidFinishImplFrame();

    begin_frame_args.frame_time = halfway_through_animation;
    host_impl_->WillBeginImplFrame(begin_frame_args);
    host_impl_->Animate();
    EXPECT_TRUE(did_request_redraw_);
    host_impl_->DidFinishImplFrame();

    begin_frame_args.frame_time = end_time;
    host_impl_->WillBeginImplFrame(begin_frame_args);
    host_impl_->Animate();
    EXPECT_TRUE(did_request_commit_);
    host_impl_->DidFinishImplFrame();

    scoped_ptr<ScrollAndScaleSet> scroll_info =
        host_impl_->ProcessScrollDeltas();
    EXPECT_EQ(scroll_info->page_scale_delta, 1);
    ExpectNone(*scroll_info, scroll_layer->id());
  }
}

TEST_F(LayerTreeHostImplTest, PageScaleAnimationTransferedOnSyncTreeActivate) {
  host_impl_->CreatePendingTree();
  host_impl_->pending_tree()->PushPageScaleFromMainThread(1.f, 1.f, 1.f);
  CreateScrollAndContentsLayers(
      host_impl_->pending_tree(),
      gfx::Size(100, 100));
  host_impl_->pending_tree()->BuildPropertyTreesForTesting();
  host_impl_->ActivateSyncTree();
  DrawFrame();

  LayerImpl* scroll_layer = host_impl_->InnerViewportScrollLayer();
  DCHECK(scroll_layer);

  float min_page_scale = 0.5f;
  float max_page_scale = 4.f;
  host_impl_->sync_tree()->PushPageScaleFromMainThread(1.f, min_page_scale,
                                                       max_page_scale);
  host_impl_->ActivateSyncTree();

  base::TimeTicks start_time = base::TimeTicks() +
                               base::TimeDelta::FromSeconds(1);
  base::TimeDelta duration = base::TimeDelta::FromMilliseconds(100);
  base::TimeTicks third_through_animation = start_time + duration / 3;
  base::TimeTicks halfway_through_animation = start_time + duration / 2;
  base::TimeTicks end_time = start_time + duration;
  float target_scale = 2.f;

  BeginFrameArgs begin_frame_args =
      CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE);

  scroll_layer->layer_tree_impl()
      ->property_trees()
      ->scroll_tree.UpdateScrollOffsetBaseForTesting(scroll_layer->id(),
                                                     gfx::ScrollOffset(50, 50));

  // Make sure TakePageScaleAnimation works properly.

  host_impl_->sync_tree()->SetPendingPageScaleAnimation(
      scoped_ptr<PendingPageScaleAnimation>(new PendingPageScaleAnimation(
          gfx::Vector2d(),
          false,
          target_scale,
          duration)));
  scoped_ptr<PendingPageScaleAnimation> psa =
      host_impl_->sync_tree()->TakePendingPageScaleAnimation();
  EXPECT_EQ(target_scale, psa->scale);
  EXPECT_EQ(duration, psa->duration);
  EXPECT_EQ(nullptr, host_impl_->sync_tree()->TakePendingPageScaleAnimation());

  // Recreate the PSA. Nothing should happen here since the tree containing the
  // PSA hasn't been activated yet.
  did_request_redraw_ = false;
  did_request_next_frame_ = false;
  host_impl_->sync_tree()->SetPendingPageScaleAnimation(
      scoped_ptr<PendingPageScaleAnimation>(new PendingPageScaleAnimation(
          gfx::Vector2d(),
          false,
          target_scale,
          duration)));
  begin_frame_args.frame_time = halfway_through_animation;
  host_impl_->WillBeginImplFrame(begin_frame_args);
  host_impl_->Animate();
  EXPECT_FALSE(did_request_next_frame_);
  EXPECT_FALSE(did_request_redraw_);
  host_impl_->DidFinishImplFrame();

  // Activate the sync tree. This should cause the animation to become enabled.
  // It should also clear the pointer on the sync tree.
  host_impl_->ActivateSyncTree();
  EXPECT_EQ(nullptr,
      host_impl_->sync_tree()->TakePendingPageScaleAnimation().get());
  EXPECT_FALSE(did_request_redraw_);
  EXPECT_TRUE(did_request_next_frame_);

  start_time += base::TimeDelta::FromSeconds(10);
  third_through_animation += base::TimeDelta::FromSeconds(10);
  halfway_through_animation += base::TimeDelta::FromSeconds(10);
  end_time += base::TimeDelta::FromSeconds(10);

  // From here on, make sure the animation runs as normal.
  did_request_redraw_ = false;
  did_request_next_frame_ = false;
  begin_frame_args.frame_time = start_time;
  host_impl_->WillBeginImplFrame(begin_frame_args);
  host_impl_->Animate();
  EXPECT_TRUE(did_request_redraw_);
  EXPECT_TRUE(did_request_next_frame_);
  host_impl_->DidFinishImplFrame();

  did_request_redraw_ = false;
  did_request_next_frame_ = false;
  begin_frame_args.frame_time = third_through_animation;
  host_impl_->WillBeginImplFrame(begin_frame_args);
  host_impl_->Animate();
  EXPECT_TRUE(did_request_redraw_);
  EXPECT_TRUE(did_request_next_frame_);
  host_impl_->DidFinishImplFrame();

  // Another activation shouldn't have any effect on the animation.
  host_impl_->ActivateSyncTree();

  did_request_redraw_ = false;
  did_request_next_frame_ = false;
  begin_frame_args.frame_time = halfway_through_animation;
  host_impl_->WillBeginImplFrame(begin_frame_args);
  host_impl_->Animate();
  EXPECT_TRUE(did_request_redraw_);
  EXPECT_TRUE(did_request_next_frame_);
  host_impl_->DidFinishImplFrame();

  did_request_redraw_ = false;
  did_request_next_frame_ = false;
  did_request_commit_ = false;
  begin_frame_args.frame_time = end_time;
  host_impl_->WillBeginImplFrame(begin_frame_args);
  host_impl_->Animate();
  EXPECT_TRUE(did_request_commit_);
  EXPECT_FALSE(did_request_next_frame_);
  host_impl_->DidFinishImplFrame();

  scoped_ptr<ScrollAndScaleSet> scroll_info =
      host_impl_->ProcessScrollDeltas();
  EXPECT_EQ(scroll_info->page_scale_delta, target_scale);
  EXPECT_TRUE(ScrollInfoContains(*scroll_info, scroll_layer->id(),
                                 gfx::Vector2d(-50, -50)));
}

TEST_F(LayerTreeHostImplTest, PageScaleAnimationCompletedNotification) {
  SetupScrollAndContentsLayers(gfx::Size(100, 100));
  host_impl_->SetViewportSize(gfx::Size(50, 50));
  DrawFrame();

  LayerImpl* scroll_layer = host_impl_->InnerViewportScrollLayer();
  DCHECK(scroll_layer);

  base::TimeTicks start_time =
      base::TimeTicks() + base::TimeDelta::FromSeconds(1);
  base::TimeDelta duration = base::TimeDelta::FromMilliseconds(100);
  base::TimeTicks halfway_through_animation = start_time + duration / 2;
  base::TimeTicks end_time = start_time + duration;

  BeginFrameArgs begin_frame_args =
      CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE);

  host_impl_->active_tree()->PushPageScaleFromMainThread(1.f, 0.5f, 4.f);
  scroll_layer->layer_tree_impl()
      ->property_trees()
      ->scroll_tree.UpdateScrollOffsetBaseForTesting(scroll_layer->id(),
                                                     gfx::ScrollOffset(50, 50));

  did_complete_page_scale_animation_ = false;
  host_impl_->active_tree()->SetPendingPageScaleAnimation(
      scoped_ptr<PendingPageScaleAnimation>(new PendingPageScaleAnimation(
          gfx::Vector2d(), false, 2.f, duration)));
  host_impl_->ActivateSyncTree();
  begin_frame_args.frame_time = start_time;
  host_impl_->WillBeginImplFrame(begin_frame_args);
  host_impl_->Animate();
  EXPECT_FALSE(did_complete_page_scale_animation_);
  host_impl_->DidFinishImplFrame();

  begin_frame_args.frame_time = halfway_through_animation;
  host_impl_->WillBeginImplFrame(begin_frame_args);
  host_impl_->Animate();
  EXPECT_FALSE(did_complete_page_scale_animation_);
  host_impl_->DidFinishImplFrame();

  begin_frame_args.frame_time = end_time;
  host_impl_->WillBeginImplFrame(begin_frame_args);
  host_impl_->Animate();
  EXPECT_TRUE(did_complete_page_scale_animation_);
  host_impl_->DidFinishImplFrame();
}

TEST_F(LayerTreeHostImplTest, MaxScrollOffsetAffectedByBoundsDelta) {
  SetupScrollAndContentsLayers(gfx::Size(100, 100));
  host_impl_->SetViewportSize(gfx::Size(50, 50));
  host_impl_->active_tree()->PushPageScaleFromMainThread(1.f, 0.5f, 4.f);
  SetNeedsRebuildPropertyTrees();
  DrawFrame();

  LayerImpl* inner_scroll = host_impl_->InnerViewportScrollLayer();
  LayerImpl* inner_container = inner_scroll->scroll_clip_layer();
  DCHECK(inner_scroll);
  DCHECK(inner_container);
  EXPECT_EQ(gfx::ScrollOffset(50, 50), inner_scroll->MaxScrollOffset());

  inner_container->SetBoundsDelta(gfx::Vector2dF(15.f, 15.f));
  inner_scroll->SetBoundsDelta(gfx::Vector2dF(7.f, 7.f));
  EXPECT_EQ(gfx::ScrollOffset(42, 42), inner_scroll->MaxScrollOffset());

  inner_container->SetBoundsDelta(gfx::Vector2dF());
  inner_scroll->SetBoundsDelta(gfx::Vector2dF());
  inner_scroll->SetBounds(gfx::Size());
  SetNeedsRebuildPropertyTrees();
  DrawFrame();

  inner_scroll->SetBoundsDelta(gfx::Vector2dF(60.f, 60.f));
  EXPECT_EQ(gfx::ScrollOffset(10, 10), inner_scroll->MaxScrollOffset());
}

class LayerTreeHostImplOverridePhysicalTime : public LayerTreeHostImpl {
 public:
  LayerTreeHostImplOverridePhysicalTime(
      const LayerTreeSettings& settings,
      LayerTreeHostImplClient* client,
      TaskRunnerProvider* task_runner_provider,
      SharedBitmapManager* manager,
      TaskGraphRunner* task_graph_runner,
      RenderingStatsInstrumentation* rendering_stats_instrumentation)
      : LayerTreeHostImpl(settings,
                          client,
                          task_runner_provider,
                          rendering_stats_instrumentation,
                          manager,
                          nullptr,
                          task_graph_runner,
                          0) {}

  BeginFrameArgs CurrentBeginFrameArgs() const override {
    return CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE,
                                          fake_current_physical_time_);
  }

  void SetCurrentPhysicalTimeTicksForTest(base::TimeTicks fake_now) {
    fake_current_physical_time_ = fake_now;
  }

 private:
  base::TimeTicks fake_current_physical_time_;
};

class LayerTreeHostImplTestScrollbarAnimation : public LayerTreeHostImplTest {
 protected:
  void SetupLayers(LayerTreeSettings settings) {
    gfx::Size content_size(100, 100);

    LayerTreeHostImplOverridePhysicalTime* host_impl_override_time =
        new LayerTreeHostImplOverridePhysicalTime(
            settings, this, &task_runner_provider_, &shared_bitmap_manager_,
            &task_graph_runner_, &stats_instrumentation_);
    host_impl_ = make_scoped_ptr(host_impl_override_time);
    output_surface_ = CreateOutputSurface();
    host_impl_->SetVisible(true);
    host_impl_->InitializeRenderer(output_surface_.get());

    SetupScrollAndContentsLayers(content_size);
    host_impl_->active_tree()->PushPageScaleFromMainThread(1.f, 1.f, 4.f);
    host_impl_->SetViewportSize(
        gfx::Size(content_size.width() / 2, content_size.height() / 2));

    scoped_ptr<SolidColorScrollbarLayerImpl> scrollbar =
        SolidColorScrollbarLayerImpl::Create(host_impl_->active_tree(), 400,
                                             VERTICAL, 10, 0, false, true);
    EXPECT_FLOAT_EQ(0.f, scrollbar->opacity());

    LayerImpl* scroll = host_impl_->active_tree()->OuterViewportScrollLayer();
    LayerImpl* root = host_impl_->active_tree()->InnerViewportContainerLayer();
    scrollbar->SetScrollLayerId(scroll->id());
    root->AddChild(std::move(scrollbar));

    host_impl_->active_tree()->DidBecomeActive();
    SetNeedsRebuildPropertyTrees();
    DrawFrame();
  }

  void RunTest(LayerTreeSettings::ScrollbarAnimator animator) {
    LayerTreeSettings settings = DefaultSettings();
    settings.scrollbar_animator = animator;
    settings.scrollbar_fade_delay_ms = 20;
    settings.scrollbar_fade_duration_ms = 20;

    SetupLayers(settings);

    base::TimeTicks fake_now = base::TimeTicks::Now();

    // A task will be posted to fade the initial scrollbar.
    EXPECT_FALSE(did_request_next_frame_);
    EXPECT_FALSE(did_request_redraw_);
    EXPECT_FALSE(animation_task_.Equals(base::Closure()));
    requested_animation_delay_ = base::TimeDelta();
    animation_task_ = base::Closure();

    // If no scroll happened during a scroll gesture, it should have no effect.
    host_impl_->ScrollBegin(BeginState(gfx::Point()).get(),
                            InputHandler::WHEEL);
    host_impl_->ScrollEnd(EndState().get());
    EXPECT_FALSE(did_request_next_frame_);
    EXPECT_FALSE(did_request_redraw_);
    EXPECT_EQ(base::TimeDelta(), requested_animation_delay_);
    EXPECT_TRUE(animation_task_.Equals(base::Closure()));

    // Before the scrollbar animation exists, we should not get redraws.
    BeginFrameArgs begin_frame_args =
        CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE, fake_now);
    host_impl_->WillBeginImplFrame(begin_frame_args);
    host_impl_->Animate();
    EXPECT_FALSE(did_request_next_frame_);
    did_request_next_frame_ = false;
    EXPECT_FALSE(did_request_redraw_);
    did_request_redraw_ = false;
    EXPECT_EQ(base::TimeDelta(), requested_animation_delay_);
    EXPECT_TRUE(animation_task_.Equals(base::Closure()));
    host_impl_->DidFinishImplFrame();

    // After a scroll, a scrollbar animation should be scheduled about 20ms from
    // now.
    host_impl_->ScrollBegin(BeginState(gfx::Point()).get(),
                            InputHandler::WHEEL);
    host_impl_->ScrollBy(UpdateState(gfx::Point(), gfx::Vector2dF(0, 5)).get());
    EXPECT_FALSE(did_request_next_frame_);
    EXPECT_TRUE(did_request_redraw_);
    did_request_redraw_ = false;
    EXPECT_EQ(base::TimeDelta(), requested_animation_delay_);
    EXPECT_TRUE(animation_task_.Equals(base::Closure()));

    host_impl_->ScrollEnd(EndState().get());
    EXPECT_FALSE(did_request_next_frame_);
    EXPECT_FALSE(did_request_redraw_);
    EXPECT_EQ(base::TimeDelta::FromMilliseconds(20),
              requested_animation_delay_);
    EXPECT_FALSE(animation_task_.Equals(base::Closure()));

    // Before the scrollbar animation begins, we should not get redraws.
    begin_frame_args =
        CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE, fake_now);
    host_impl_->WillBeginImplFrame(begin_frame_args);
    host_impl_->Animate();
    EXPECT_FALSE(did_request_next_frame_);
    did_request_next_frame_ = false;
    EXPECT_FALSE(did_request_redraw_);
    did_request_redraw_ = false;
    host_impl_->DidFinishImplFrame();

    // Start the scrollbar animation.
    fake_now += requested_animation_delay_;
    requested_animation_delay_ = base::TimeDelta();
    animation_task_.Run();
    animation_task_ = base::Closure();
    EXPECT_TRUE(did_request_next_frame_);
    did_request_next_frame_ = false;
    EXPECT_FALSE(did_request_redraw_);

    // After the scrollbar animation begins, we should start getting redraws.
    begin_frame_args =
        CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE, fake_now);
    host_impl_->WillBeginImplFrame(begin_frame_args);
    host_impl_->Animate();
    EXPECT_TRUE(did_request_next_frame_);
    did_request_next_frame_ = false;
    EXPECT_TRUE(did_request_redraw_);
    did_request_redraw_ = false;
    EXPECT_EQ(base::TimeDelta(), requested_animation_delay_);
    EXPECT_TRUE(animation_task_.Equals(base::Closure()));
    host_impl_->DidFinishImplFrame();

    // Setting the scroll offset outside a scroll should also cause the
    // scrollbar to appear and to schedule a scrollbar animation.
    if (host_impl_->active_tree()
            ->property_trees()
            ->scroll_tree.UpdateScrollOffsetBaseForTesting(
                host_impl_->InnerViewportScrollLayer()->id(),
                gfx::ScrollOffset(5, 5)))
      host_impl_->active_tree()->DidUpdateScrollOffset(
          host_impl_->InnerViewportScrollLayer()->id(),
          host_impl_->InnerViewportScrollLayer()->transform_tree_index());
    EXPECT_FALSE(did_request_next_frame_);
    EXPECT_FALSE(did_request_redraw_);
    EXPECT_EQ(base::TimeDelta::FromMilliseconds(20),
              requested_animation_delay_);
    EXPECT_FALSE(animation_task_.Equals(base::Closure()));
    requested_animation_delay_ = base::TimeDelta();
    animation_task_ = base::Closure();

    // Scrolling should have stopped the animation, so we should not be getting
    // redraws.
    begin_frame_args =
        CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE, fake_now);
    host_impl_->WillBeginImplFrame(begin_frame_args);
    host_impl_->Animate();
    EXPECT_FALSE(did_request_next_frame_);
    did_request_next_frame_ = false;
    EXPECT_FALSE(did_request_redraw_);
    did_request_redraw_ = false;
    host_impl_->DidFinishImplFrame();

    // Scrollbar animation is not triggered unnecessarily.
    host_impl_->ScrollBegin(BeginState(gfx::Point()).get(),
                            InputHandler::WHEEL);
    host_impl_->ScrollBy(UpdateState(gfx::Point(), gfx::Vector2dF(5, 0)).get());
    EXPECT_FALSE(did_request_next_frame_);
    EXPECT_TRUE(did_request_redraw_);
    did_request_redraw_ = false;
    EXPECT_EQ(base::TimeDelta(), requested_animation_delay_);
    EXPECT_TRUE(animation_task_.Equals(base::Closure()));

    host_impl_->ScrollEnd(EndState().get());
    EXPECT_FALSE(did_request_next_frame_);
    EXPECT_FALSE(did_request_redraw_);
    EXPECT_EQ(base::TimeDelta(), requested_animation_delay_);
    EXPECT_TRUE(animation_task_.Equals(base::Closure()));

    // Changing page scale triggers scrollbar animation.
    host_impl_->active_tree()->PushPageScaleFromMainThread(1.f, 1.f, 4.f);
    host_impl_->active_tree()->SetPageScaleOnActiveTree(1.1f);
    EXPECT_FALSE(did_request_next_frame_);
    EXPECT_FALSE(did_request_redraw_);
    EXPECT_EQ(base::TimeDelta::FromMilliseconds(20),
              requested_animation_delay_);
    EXPECT_FALSE(animation_task_.Equals(base::Closure()));
    requested_animation_delay_ = base::TimeDelta();
    animation_task_ = base::Closure();
  }
};

TEST_F(LayerTreeHostImplTestScrollbarAnimation, LinearFade) {
  RunTest(LayerTreeSettings::LINEAR_FADE);
}

TEST_F(LayerTreeHostImplTestScrollbarAnimation, Thinning) {
  RunTest(LayerTreeSettings::THINNING);
}

class LayerTreeHostImplTestScrollbarOpacity : public LayerTreeHostImplTest {
 protected:
  void RunTest(LayerTreeSettings::ScrollbarAnimator animator) {
    LayerTreeSettings settings = DefaultSettings();
    settings.scrollbar_animator = animator;
    settings.scrollbar_fade_delay_ms = 20;
    settings.scrollbar_fade_duration_ms = 20;
    gfx::Size content_size(100, 100);

    CreateHostImpl(settings, CreateOutputSurface());
    host_impl_->CreatePendingTree();
    CreateScrollAndContentsLayers(host_impl_->pending_tree(), content_size);
    scoped_ptr<SolidColorScrollbarLayerImpl> scrollbar =
        SolidColorScrollbarLayerImpl::Create(host_impl_->pending_tree(), 400,
                                             VERTICAL, 10, 0, false, true);
    LayerImpl* scroll = host_impl_->pending_tree()->OuterViewportScrollLayer();
    LayerImpl* root = host_impl_->pending_tree()->InnerViewportContainerLayer();
    scrollbar->SetScrollLayerId(scroll->id());
    root->AddChild(std::move(scrollbar));
    host_impl_->pending_tree()->PushPageScaleFromMainThread(1.f, 1.f, 1.f);
    host_impl_->pending_tree()->BuildPropertyTreesForTesting();
    host_impl_->ActivateSyncTree();

    LayerImpl* scrollbar_layer = host_impl_->active_tree()->LayerById(400);

    EffectNode* active_tree_node =
        host_impl_->active_tree()->property_trees()->effect_tree.Node(
            scrollbar_layer->effect_tree_index());
    EXPECT_FLOAT_EQ(scrollbar_layer->opacity(), active_tree_node->data.opacity);

    host_impl_->ScrollbarAnimationControllerForId(scroll->id())
        ->DidMouseMoveNear(0);
    host_impl_->ScrollBegin(BeginState(gfx::Point()).get(),
                            InputHandler::WHEEL);
    host_impl_->ScrollBy(UpdateState(gfx::Point(), gfx::Vector2dF(0, 5)).get());
    host_impl_->ScrollEnd(EndState().get());
    host_impl_->CreatePendingTree();
    EffectNode* pending_tree_node =
        host_impl_->pending_tree()->property_trees()->effect_tree.Node(
            scrollbar_layer->effect_tree_index());
    EXPECT_FLOAT_EQ(1.f, active_tree_node->data.opacity);
    EXPECT_FLOAT_EQ(1.f, scrollbar_layer->opacity());
    EXPECT_FLOAT_EQ(0.f, pending_tree_node->data.opacity);
    host_impl_->ActivateSyncTree();
    active_tree_node =
        host_impl_->active_tree()->property_trees()->effect_tree.Node(
            scrollbar_layer->effect_tree_index());
    EXPECT_FLOAT_EQ(1.f, active_tree_node->data.opacity);
    EXPECT_FLOAT_EQ(1.f, scrollbar_layer->opacity());
  }
};

TEST_F(LayerTreeHostImplTestScrollbarOpacity, LinearFade) {
  RunTest(LayerTreeSettings::LINEAR_FADE);
}

TEST_F(LayerTreeHostImplTestScrollbarOpacity, Thinning) {
  RunTest(LayerTreeSettings::THINNING);
}

TEST_F(LayerTreeHostImplTest, ScrollbarInnerLargerThanOuter) {
  LayerTreeSettings settings = DefaultSettings();
  CreateHostImpl(settings, CreateOutputSurface());

  gfx::Size inner_viewport_size(315, 200);
  gfx::Size outer_viewport_size(300, 200);
  gfx::Size content_size(1000, 1000);

  const int horiz_id = 11;
  const int child_clip_id = 14;
  const int child_scroll_id = 15;

  CreateScrollAndContentsLayers(host_impl_->active_tree(), content_size);
  host_impl_->active_tree()->InnerViewportContainerLayer()->SetBounds(
      inner_viewport_size);
  host_impl_->active_tree()->OuterViewportContainerLayer()->SetBounds(
      outer_viewport_size);
  LayerImpl* root_scroll =
      host_impl_->active_tree()->OuterViewportScrollLayer();
  scoped_ptr<SolidColorScrollbarLayerImpl> horiz_scrollbar =
      SolidColorScrollbarLayerImpl::Create(host_impl_->active_tree(), horiz_id,
                                           HORIZONTAL, 5, 5, true, true);
  scoped_ptr<LayerImpl> child =
      LayerImpl::Create(host_impl_->active_tree(), child_scroll_id);
  child->SetBounds(content_size);
  scoped_ptr<LayerImpl> child_clip =
      LayerImpl::Create(host_impl_->active_tree(), child_clip_id);
  child->SetBounds(inner_viewport_size);

  horiz_scrollbar->SetScrollLayerId(root_scroll->id());

  EXPECT_EQ(300, horiz_scrollbar->clip_layer_length());
}

TEST_F(LayerTreeHostImplTest, ScrollbarRegistration) {
  LayerTreeSettings settings = DefaultSettings();
  settings.scrollbar_animator = LayerTreeSettings::LINEAR_FADE;
  settings.scrollbar_fade_delay_ms = 20;
  settings.scrollbar_fade_duration_ms = 20;
  CreateHostImpl(settings, CreateOutputSurface());

  gfx::Size viewport_size(300, 200);
  gfx::Size content_size(1000, 1000);

  const int vert_1_id = 10;
  const int horiz_1_id = 11;
  const int vert_2_id = 12;
  const int horiz_2_id = 13;
  const int child_clip_id = 14;
  const int child_scroll_id = 15;

  CreateScrollAndContentsLayers(host_impl_->active_tree(), content_size);
  host_impl_->active_tree()->InnerViewportContainerLayer()->SetBounds(
      viewport_size);
  LayerImpl* root_scroll =
      host_impl_->active_tree()->OuterViewportScrollLayer();
  scoped_ptr<SolidColorScrollbarLayerImpl> vert_1_scrollbar =
      SolidColorScrollbarLayerImpl::Create(host_impl_->active_tree(), vert_1_id,
                                           VERTICAL, 5, 5, true, true);
  scoped_ptr<SolidColorScrollbarLayerImpl> horiz_1_scrollbar =
      SolidColorScrollbarLayerImpl::Create(
          host_impl_->active_tree(), horiz_1_id, HORIZONTAL, 5, 5, true, true);
  scoped_ptr<SolidColorScrollbarLayerImpl> vert_2_scrollbar =
      SolidColorScrollbarLayerImpl::Create(host_impl_->active_tree(), vert_2_id,
                                           VERTICAL, 5, 5, true, true);
  scoped_ptr<SolidColorScrollbarLayerImpl> horiz_2_scrollbar =
      SolidColorScrollbarLayerImpl::Create(
          host_impl_->active_tree(), horiz_2_id, HORIZONTAL, 5, 5, true, true);
  scoped_ptr<LayerImpl> child =
      LayerImpl::Create(host_impl_->active_tree(), child_scroll_id);
  child->SetBounds(content_size);
  scoped_ptr<LayerImpl> child_clip =
      LayerImpl::Create(host_impl_->active_tree(), child_clip_id);
  child->SetBounds(viewport_size);
  LayerImpl* child_ptr = child.get();
  LayerImpl* child_clip_ptr = child_clip.get();

  // Check scrollbar registration on the viewport layers.
  EXPECT_EQ(0ul, host_impl_->ScrollbarsFor(root_scroll->id()).size());
  EXPECT_EQ(nullptr,
            host_impl_->ScrollbarAnimationControllerForId(root_scroll->id()));
  vert_1_scrollbar->SetScrollLayerId(root_scroll->id());
  EXPECT_EQ(1ul, host_impl_->ScrollbarsFor(root_scroll->id()).size());
  EXPECT_TRUE(host_impl_->ScrollbarAnimationControllerForId(root_scroll->id()));
  horiz_1_scrollbar->SetScrollLayerId(root_scroll->id());
  EXPECT_EQ(2ul, host_impl_->ScrollbarsFor(root_scroll->id()).size());
  EXPECT_TRUE(host_impl_->ScrollbarAnimationControllerForId(root_scroll->id()));

  // Changing one of the viewport layers should result in a scrollbar animation
  // update.
  animation_task_ = base::Closure();
  host_impl_->active_tree()->InnerViewportContainerLayer()->SetBoundsDelta(
      gfx::Vector2dF(10, 10));
  EXPECT_FALSE(animation_task_.Equals(base::Closure()));
  animation_task_ = base::Closure();
  host_impl_->active_tree()->OuterViewportScrollLayer()->SetCurrentScrollOffset(
      gfx::ScrollOffset(10, 10));
  EXPECT_FALSE(animation_task_.Equals(base::Closure()));
  animation_task_ = base::Closure();
  host_impl_->active_tree()->InnerViewportScrollLayer()->SetCurrentScrollOffset(
      gfx::ScrollOffset(10, 10));
  EXPECT_FALSE(animation_task_.Equals(base::Closure()));
  animation_task_ = base::Closure();

  // Check scrollbar registration on a sublayer.
  child->SetScrollClipLayer(child_clip->id());
  child_clip->AddChild(std::move(child));
  root_scroll->AddChild(std::move(child_clip));
  EXPECT_EQ(0ul, host_impl_->ScrollbarsFor(child_scroll_id).size());
  EXPECT_EQ(nullptr,
            host_impl_->ScrollbarAnimationControllerForId(child_scroll_id));
  vert_2_scrollbar->SetScrollLayerId(child_scroll_id);
  EXPECT_EQ(1ul, host_impl_->ScrollbarsFor(child_scroll_id).size());
  EXPECT_TRUE(host_impl_->ScrollbarAnimationControllerForId(child_scroll_id));
  horiz_2_scrollbar->SetScrollLayerId(child_scroll_id);
  EXPECT_EQ(2ul, host_impl_->ScrollbarsFor(child_scroll_id).size());
  EXPECT_TRUE(host_impl_->ScrollbarAnimationControllerForId(child_scroll_id));

  // Changing one of the child layers should result in a scrollbar animation
  // update.
  animation_task_ = base::Closure();
  child_clip_ptr->SetBounds(gfx::Size(200, 200));
  EXPECT_FALSE(animation_task_.Equals(base::Closure()));
  animation_task_ = base::Closure();
  child_ptr->SetCurrentScrollOffset(gfx::ScrollOffset(10, 10));
  EXPECT_FALSE(animation_task_.Equals(base::Closure()));
  animation_task_ = base::Closure();

  // Check scrollbar unregistration.
  vert_1_scrollbar.reset();
  EXPECT_EQ(1ul, host_impl_->ScrollbarsFor(root_scroll->id()).size());
  EXPECT_TRUE(host_impl_->ScrollbarAnimationControllerForId(root_scroll->id()));
  horiz_1_scrollbar.reset();
  EXPECT_EQ(0ul, host_impl_->ScrollbarsFor(root_scroll->id()).size());
  EXPECT_EQ(nullptr,
            host_impl_->ScrollbarAnimationControllerForId(root_scroll->id()));

  EXPECT_EQ(2ul, host_impl_->ScrollbarsFor(child_scroll_id).size());
  vert_2_scrollbar.reset();
  EXPECT_EQ(1ul, host_impl_->ScrollbarsFor(child_scroll_id).size());
  EXPECT_TRUE(host_impl_->ScrollbarAnimationControllerForId(child_scroll_id));
  horiz_2_scrollbar.reset();
  EXPECT_EQ(0ul, host_impl_->ScrollbarsFor(child_scroll_id).size());
  EXPECT_EQ(nullptr,
            host_impl_->ScrollbarAnimationControllerForId(root_scroll->id()));

  // Changing scroll offset should no longer trigger any animation.
  host_impl_->active_tree()->InnerViewportScrollLayer()->SetCurrentScrollOffset(
      gfx::ScrollOffset(20, 20));
  EXPECT_TRUE(animation_task_.Equals(base::Closure()));
  child_ptr->SetCurrentScrollOffset(gfx::ScrollOffset(20, 20));
  EXPECT_TRUE(animation_task_.Equals(base::Closure()));
}

void LayerTreeHostImplTest::SetupMouseMoveAtWithDeviceScale(
    float device_scale_factor) {
  LayerTreeSettings settings = DefaultSettings();
  settings.scrollbar_fade_delay_ms = 500;
  settings.scrollbar_fade_duration_ms = 300;
  settings.scrollbar_animator = LayerTreeSettings::THINNING;

  gfx::Size viewport_size(300, 200);
  gfx::Size device_viewport_size =
      gfx::ScaleToFlooredSize(viewport_size, device_scale_factor);
  gfx::Size content_size(1000, 1000);
  gfx::Size scrollbar_size(gfx::Size(15, viewport_size.height()));

  CreateHostImpl(settings, CreateOutputSurface());
  host_impl_->active_tree()->SetDeviceScaleFactor(device_scale_factor);
  host_impl_->SetViewportSize(device_viewport_size);

  CreateScrollAndContentsLayers(host_impl_->active_tree(), content_size);
  host_impl_->active_tree()->InnerViewportContainerLayer()->SetBounds(
      viewport_size);
  LayerImpl* root_scroll =
      host_impl_->active_tree()->OuterViewportScrollLayer();
  // The scrollbar is on the left side.
  scoped_ptr<SolidColorScrollbarLayerImpl> scrollbar =
      SolidColorScrollbarLayerImpl::Create(host_impl_->active_tree(), 6,
                                           VERTICAL, 5, 5, true, true);
  scrollbar->SetScrollLayerId(root_scroll->id());
  scrollbar->SetDrawsContent(true);
  scrollbar->SetBounds(scrollbar_size);
  scrollbar->SetTouchEventHandlerRegion(gfx::Rect(scrollbar_size));
  host_impl_->active_tree()->InnerViewportContainerLayer()->AddChild(
      std::move(scrollbar));
  host_impl_->active_tree()->DidBecomeActive();

  DrawFrame();
  host_impl_->active_tree()->UpdateDrawProperties(false);

  ScrollbarAnimationControllerThinning* scrollbar_animation_controller =
      static_cast<ScrollbarAnimationControllerThinning*>(
          host_impl_->ScrollbarAnimationControllerForId(root_scroll->id()));
  scrollbar_animation_controller->set_mouse_move_distance_for_test(100.f);

  host_impl_->MouseMoveAt(gfx::Point(200, 1));
  EXPECT_FALSE(scrollbar_animation_controller->mouse_is_near_scrollbar());

  host_impl_->MouseMoveAt(gfx::Point(100, 50));
  EXPECT_TRUE(scrollbar_animation_controller->mouse_is_near_scrollbar());

  host_impl_->MouseMoveAt(gfx::Point(116, 100));
  EXPECT_FALSE(scrollbar_animation_controller->mouse_is_near_scrollbar());

  scrollbar_animation_controller->set_mouse_move_distance_for_test(102.f);
  host_impl_->MouseMoveAt(gfx::Point(116, 100));
  EXPECT_TRUE(scrollbar_animation_controller->mouse_is_near_scrollbar());

  did_request_redraw_ = false;
  EXPECT_EQ(Layer::INVALID_ID,
            host_impl_->scroll_layer_id_when_mouse_over_scrollbar());
  host_impl_->MouseMoveAt(gfx::Point(10, 100));
  EXPECT_EQ(117, host_impl_->scroll_layer_id_when_mouse_over_scrollbar());
  host_impl_->MouseMoveAt(gfx::Point(10, 120));
  EXPECT_EQ(117, host_impl_->scroll_layer_id_when_mouse_over_scrollbar());
  host_impl_->MouseMoveAt(gfx::Point(150, 120));
  EXPECT_EQ(Layer::INVALID_ID,
            host_impl_->scroll_layer_id_when_mouse_over_scrollbar());
}

TEST_F(LayerTreeHostImplTest, MouseMoveAtWithDeviceScaleOf1) {
  SetupMouseMoveAtWithDeviceScale(1.f);
}

TEST_F(LayerTreeHostImplTest, MouseMoveAtWithDeviceScaleOf2) {
  SetupMouseMoveAtWithDeviceScale(2.f);
}

TEST_F(LayerTreeHostImplTest, CompositorFrameMetadata) {
  SetupScrollAndContentsLayers(gfx::Size(100, 100));
  host_impl_->SetViewportSize(gfx::Size(50, 50));
  host_impl_->active_tree()->PushPageScaleFromMainThread(1.f, 0.5f, 4.f);
  DrawFrame();
  {
    CompositorFrameMetadata metadata =
        host_impl_->MakeCompositorFrameMetadata();
    EXPECT_EQ(gfx::Vector2dF(), metadata.root_scroll_offset);
    EXPECT_EQ(1.f, metadata.page_scale_factor);
    EXPECT_EQ(gfx::SizeF(50.f, 50.f), metadata.scrollable_viewport_size);
    EXPECT_EQ(gfx::SizeF(100.f, 100.f), metadata.root_layer_size);
    EXPECT_EQ(0.5f, metadata.min_page_scale_factor);
    EXPECT_EQ(4.f, metadata.max_page_scale_factor);
    EXPECT_FALSE(metadata.root_overflow_x_hidden);
    EXPECT_FALSE(metadata.root_overflow_y_hidden);
  }

  // Scrolling should update metadata immediately.
  EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
            host_impl_->ScrollBegin(BeginState(gfx::Point()).get(),
                                    InputHandler::WHEEL)
                .thread);
  host_impl_->ScrollBy(UpdateState(gfx::Point(), gfx::Vector2d(0, 10)).get());
  {
    CompositorFrameMetadata metadata =
        host_impl_->MakeCompositorFrameMetadata();
    EXPECT_EQ(gfx::Vector2dF(0.f, 10.f), metadata.root_scroll_offset);
  }
  host_impl_->ScrollEnd(EndState().get());
  {
    CompositorFrameMetadata metadata =
        host_impl_->MakeCompositorFrameMetadata();
    EXPECT_EQ(gfx::Vector2dF(0.f, 10.f), metadata.root_scroll_offset);
  }

  // Root "overflow: hidden" properties should be reflected on the outer
  // viewport scroll layer.
  {
    host_impl_->active_tree()
        ->OuterViewportScrollLayer()
        ->set_user_scrollable_horizontal(false);
    CompositorFrameMetadata metadata =
        host_impl_->MakeCompositorFrameMetadata();
    EXPECT_TRUE(metadata.root_overflow_x_hidden);
    EXPECT_FALSE(metadata.root_overflow_y_hidden);

    host_impl_->active_tree()
        ->OuterViewportScrollLayer()
        ->set_user_scrollable_vertical(false);
    metadata = host_impl_->MakeCompositorFrameMetadata();
    EXPECT_TRUE(metadata.root_overflow_x_hidden);
    EXPECT_TRUE(metadata.root_overflow_y_hidden);
  }

  // Re-enable scrollability and verify that overflows are no longer hidden.
  {
    host_impl_->active_tree()
        ->OuterViewportScrollLayer()
        ->set_user_scrollable_horizontal(true);
    host_impl_->active_tree()
        ->OuterViewportScrollLayer()
        ->set_user_scrollable_vertical(true);
    CompositorFrameMetadata metadata =
        host_impl_->MakeCompositorFrameMetadata();
    EXPECT_FALSE(metadata.root_overflow_x_hidden);
    EXPECT_FALSE(metadata.root_overflow_y_hidden);
  }

  // Root "overflow: hidden" properties should also be reflected on the
  // inner viewport scroll layer.
  {
    host_impl_->active_tree()
        ->InnerViewportScrollLayer()
        ->set_user_scrollable_horizontal(false);
    CompositorFrameMetadata metadata =
        host_impl_->MakeCompositorFrameMetadata();
    EXPECT_TRUE(metadata.root_overflow_x_hidden);
    EXPECT_FALSE(metadata.root_overflow_y_hidden);

    host_impl_->active_tree()
        ->InnerViewportScrollLayer()
        ->set_user_scrollable_vertical(false);
    metadata = host_impl_->MakeCompositorFrameMetadata();
    EXPECT_TRUE(metadata.root_overflow_x_hidden);
    EXPECT_TRUE(metadata.root_overflow_y_hidden);
  }

  // Page scale should update metadata correctly (shrinking only the viewport).
  host_impl_->ScrollBegin(BeginState(gfx::Point()).get(),
                          InputHandler::TOUCHSCREEN);
  host_impl_->PinchGestureBegin();
  host_impl_->PinchGestureUpdate(2.f, gfx::Point());
  host_impl_->PinchGestureEnd();
  host_impl_->ScrollEnd(EndState().get());
  {
    CompositorFrameMetadata metadata =
        host_impl_->MakeCompositorFrameMetadata();
    EXPECT_EQ(gfx::Vector2dF(0.f, 10.f), metadata.root_scroll_offset);
    EXPECT_EQ(2.f, metadata.page_scale_factor);
    EXPECT_EQ(gfx::SizeF(25.f, 25.f), metadata.scrollable_viewport_size);
    EXPECT_EQ(gfx::SizeF(100.f, 100.f), metadata.root_layer_size);
    EXPECT_EQ(0.5f, metadata.min_page_scale_factor);
    EXPECT_EQ(4.f, metadata.max_page_scale_factor);
  }

  // Likewise if set from the main thread.
  host_impl_->ProcessScrollDeltas();
  host_impl_->active_tree()->PushPageScaleFromMainThread(4.f, 0.5f, 4.f);
  host_impl_->active_tree()->SetPageScaleOnActiveTree(4.f);
  {
    CompositorFrameMetadata metadata =
        host_impl_->MakeCompositorFrameMetadata();
    EXPECT_EQ(gfx::Vector2dF(0.f, 10.f), metadata.root_scroll_offset);
    EXPECT_EQ(4.f, metadata.page_scale_factor);
    EXPECT_EQ(gfx::SizeF(12.5f, 12.5f), metadata.scrollable_viewport_size);
    EXPECT_EQ(gfx::SizeF(100.f, 100.f), metadata.root_layer_size);
    EXPECT_EQ(0.5f, metadata.min_page_scale_factor);
    EXPECT_EQ(4.f, metadata.max_page_scale_factor);
  }
}

class DidDrawCheckLayer : public LayerImpl {
 public:
  static scoped_ptr<LayerImpl> Create(LayerTreeImpl* tree_impl, int id) {
    return make_scoped_ptr(new DidDrawCheckLayer(tree_impl, id));
  }

  bool WillDraw(DrawMode draw_mode, ResourceProvider* provider) override {
    will_draw_called_ = true;
    if (will_draw_returns_false_)
      return false;
    return LayerImpl::WillDraw(draw_mode, provider);
  }

  void AppendQuads(RenderPass* render_pass,
                   AppendQuadsData* append_quads_data) override {
    append_quads_called_ = true;
    LayerImpl::AppendQuads(render_pass, append_quads_data);
  }

  void DidDraw(ResourceProvider* provider) override {
    did_draw_called_ = true;
    LayerImpl::DidDraw(provider);
  }

  bool will_draw_called() const { return will_draw_called_; }
  bool append_quads_called() const { return append_quads_called_; }
  bool did_draw_called() const { return did_draw_called_; }

  void set_will_draw_returns_false() { will_draw_returns_false_ = true; }

  void ClearDidDrawCheck() {
    will_draw_called_ = false;
    append_quads_called_ = false;
    did_draw_called_ = false;
  }

  static void IgnoreResult(scoped_ptr<CopyOutputResult> result) {}

  void AddCopyRequest() {
    std::vector<scoped_ptr<CopyOutputRequest>> requests;
    requests.push_back(
        CopyOutputRequest::CreateRequest(base::Bind(&IgnoreResult)));
    SetForceRenderSurface(true);
    PassCopyRequests(&requests);
  }

 protected:
  DidDrawCheckLayer(LayerTreeImpl* tree_impl, int id)
      : LayerImpl(tree_impl, id),
        will_draw_returns_false_(false),
        will_draw_called_(false),
        append_quads_called_(false),
        did_draw_called_(false) {
    SetBounds(gfx::Size(10, 10));
    SetDrawsContent(true);
    draw_properties().visible_layer_rect = gfx::Rect(0, 0, 10, 10);
  }

 private:
  bool will_draw_returns_false_;
  bool will_draw_called_;
  bool append_quads_called_;
  bool did_draw_called_;
};

TEST_F(LayerTreeHostImplTest, WillDrawReturningFalseDoesNotCall) {
  // The root layer is always drawn, so run this test on a child layer that
  // will be masked out by the root layer's bounds.
  host_impl_->active_tree()->SetRootLayer(
      DidDrawCheckLayer::Create(host_impl_->active_tree(), 1));
  DidDrawCheckLayer* root = static_cast<DidDrawCheckLayer*>(
      host_impl_->active_tree()->root_layer());

  root->AddChild(DidDrawCheckLayer::Create(host_impl_->active_tree(), 2));
  root->SetForceRenderSurface(true);
  DidDrawCheckLayer* layer =
      static_cast<DidDrawCheckLayer*>(root->children()[0].get());

  {
    LayerTreeHostImpl::FrameData frame;
    EXPECT_EQ(DRAW_SUCCESS, PrepareToDrawFrame(&frame));
    host_impl_->DrawLayers(&frame);
    host_impl_->DidDrawAllLayers(frame);

    EXPECT_TRUE(layer->will_draw_called());
    EXPECT_TRUE(layer->append_quads_called());
    EXPECT_TRUE(layer->did_draw_called());
  }

  host_impl_->SetViewportDamage(gfx::Rect(10, 10));

  {
    LayerTreeHostImpl::FrameData frame;

    layer->set_will_draw_returns_false();
    layer->ClearDidDrawCheck();

    EXPECT_EQ(DRAW_SUCCESS, PrepareToDrawFrame(&frame));
    host_impl_->DrawLayers(&frame);
    host_impl_->DidDrawAllLayers(frame);

    EXPECT_TRUE(layer->will_draw_called());
    EXPECT_FALSE(layer->append_quads_called());
    EXPECT_FALSE(layer->did_draw_called());
  }
}

TEST_F(LayerTreeHostImplTest, DidDrawNotCalledOnHiddenLayer) {
  // The root layer is always drawn, so run this test on a child layer that
  // will be masked out by the root layer's bounds.
  host_impl_->active_tree()->SetRootLayer(
      DidDrawCheckLayer::Create(host_impl_->active_tree(), 1));
  DidDrawCheckLayer* root = static_cast<DidDrawCheckLayer*>(
      host_impl_->active_tree()->root_layer());
  root->SetMasksToBounds(true);
  root->SetForceRenderSurface(true);
  root->AddChild(DidDrawCheckLayer::Create(host_impl_->active_tree(), 2));
  DidDrawCheckLayer* layer =
      static_cast<DidDrawCheckLayer*>(root->children()[0].get());
  // Ensure visible_layer_rect for layer is empty.
  layer->SetPosition(gfx::PointF(100.f, 100.f));
  layer->SetBounds(gfx::Size(10, 10));

  LayerTreeHostImpl::FrameData frame;

  EXPECT_FALSE(layer->will_draw_called());
  EXPECT_FALSE(layer->did_draw_called());

  SetNeedsRebuildPropertyTrees();
  EXPECT_EQ(DRAW_SUCCESS, PrepareToDrawFrame(&frame));
  host_impl_->DrawLayers(&frame);
  host_impl_->DidDrawAllLayers(frame);

  EXPECT_FALSE(layer->will_draw_called());
  EXPECT_FALSE(layer->did_draw_called());

  EXPECT_TRUE(layer->visible_layer_rect().IsEmpty());

  // Ensure visible_layer_rect for layer is not empty
  layer->SetPosition(gfx::PointF());
  layer->NoteLayerPropertyChanged();

  EXPECT_FALSE(layer->will_draw_called());
  EXPECT_FALSE(layer->did_draw_called());

  SetNeedsRebuildPropertyTrees();
  EXPECT_EQ(DRAW_SUCCESS, PrepareToDrawFrame(&frame));
  host_impl_->DrawLayers(&frame);
  host_impl_->DidDrawAllLayers(frame);

  EXPECT_TRUE(layer->will_draw_called());
  EXPECT_TRUE(layer->did_draw_called());

  EXPECT_FALSE(layer->visible_layer_rect().IsEmpty());
}

TEST_F(LayerTreeHostImplTest, WillDrawNotCalledOnOccludedLayer) {
  gfx::Size big_size(1000, 1000);
  host_impl_->SetViewportSize(big_size);

  host_impl_->active_tree()->SetRootLayer(
      DidDrawCheckLayer::Create(host_impl_->active_tree(), 1));
  DidDrawCheckLayer* root =
      static_cast<DidDrawCheckLayer*>(host_impl_->active_tree()->root_layer());

  root->AddChild(DidDrawCheckLayer::Create(host_impl_->active_tree(), 2));
  DidDrawCheckLayer* occluded_layer =
      static_cast<DidDrawCheckLayer*>(root->children()[0].get());

  root->AddChild(DidDrawCheckLayer::Create(host_impl_->active_tree(), 3));
  root->SetForceRenderSurface(true);
  DidDrawCheckLayer* top_layer =
      static_cast<DidDrawCheckLayer*>(root->children()[1].get());
  // This layer covers the occluded_layer above. Make this layer large so it can
  // occlude.
  top_layer->SetBounds(big_size);
  top_layer->SetContentsOpaque(true);

  LayerTreeHostImpl::FrameData frame;

  EXPECT_FALSE(occluded_layer->will_draw_called());
  EXPECT_FALSE(occluded_layer->did_draw_called());
  EXPECT_FALSE(top_layer->will_draw_called());
  EXPECT_FALSE(top_layer->did_draw_called());

  EXPECT_EQ(DRAW_SUCCESS, PrepareToDrawFrame(&frame));
  host_impl_->DrawLayers(&frame);
  host_impl_->DidDrawAllLayers(frame);

  EXPECT_FALSE(occluded_layer->will_draw_called());
  EXPECT_FALSE(occluded_layer->did_draw_called());
  EXPECT_TRUE(top_layer->will_draw_called());
  EXPECT_TRUE(top_layer->did_draw_called());
}

TEST_F(LayerTreeHostImplTest, DidDrawCalledOnAllLayers) {
  host_impl_->active_tree()->SetRootLayer(
      DidDrawCheckLayer::Create(host_impl_->active_tree(), 1));
  DidDrawCheckLayer* root =
      static_cast<DidDrawCheckLayer*>(host_impl_->active_tree()->root_layer());

  root->AddChild(DidDrawCheckLayer::Create(host_impl_->active_tree(), 2));
  root->SetForceRenderSurface(true);
  DidDrawCheckLayer* layer1 =
      static_cast<DidDrawCheckLayer*>(root->children()[0].get());

  layer1->AddChild(DidDrawCheckLayer::Create(host_impl_->active_tree(), 3));
  DidDrawCheckLayer* layer2 =
      static_cast<DidDrawCheckLayer*>(layer1->children()[0].get());

  layer1->SetForceRenderSurface(true);
  layer1->SetShouldFlattenTransform(true);

  EXPECT_FALSE(root->did_draw_called());
  EXPECT_FALSE(layer1->did_draw_called());
  EXPECT_FALSE(layer2->did_draw_called());

  LayerTreeHostImpl::FrameData frame;
  FakeLayerTreeHostImpl::RecursiveUpdateNumChildren(
      host_impl_->active_tree()->root_layer());
  EXPECT_EQ(DRAW_SUCCESS, PrepareToDrawFrame(&frame));
  host_impl_->DrawLayers(&frame);
  host_impl_->DidDrawAllLayers(frame);

  EXPECT_TRUE(root->did_draw_called());
  EXPECT_TRUE(layer1->did_draw_called());
  EXPECT_TRUE(layer2->did_draw_called());

  EXPECT_NE(root->render_surface(), layer1->render_surface());
  EXPECT_TRUE(layer1->render_surface());
}

class MissingTextureAnimatingLayer : public DidDrawCheckLayer {
 public:
  static scoped_ptr<LayerImpl> Create(
      LayerTreeImpl* tree_impl,
      int id,
      bool tile_missing,
      bool had_incomplete_tile,
      bool animating,
      ResourceProvider* resource_provider,
      scoped_refptr<AnimationTimeline> timeline) {
    return make_scoped_ptr(new MissingTextureAnimatingLayer(
        tree_impl, id, tile_missing, had_incomplete_tile, animating,
        resource_provider, timeline));
  }

  void AppendQuads(RenderPass* render_pass,
                   AppendQuadsData* append_quads_data) override {
    LayerImpl::AppendQuads(render_pass, append_quads_data);
    if (had_incomplete_tile_)
      append_quads_data->num_incomplete_tiles++;
    if (tile_missing_)
      append_quads_data->num_missing_tiles++;
  }

 private:
  MissingTextureAnimatingLayer(LayerTreeImpl* tree_impl,
                               int id,
                               bool tile_missing,
                               bool had_incomplete_tile,
                               bool animating,
                               ResourceProvider* resource_provider,
                               scoped_refptr<AnimationTimeline> timeline)
      : DidDrawCheckLayer(tree_impl, id),
        tile_missing_(tile_missing),
        had_incomplete_tile_(had_incomplete_tile) {
    if (animating)
      AddAnimatedTransformToLayerWithPlayer(this->id(), timeline, 10.0, 3, 0);
  }

  bool tile_missing_;
  bool had_incomplete_tile_;
};

struct PrepareToDrawSuccessTestCase {
  struct State {
    bool has_missing_tile = false;
    bool has_incomplete_tile = false;
    bool is_animating = false;
    bool has_copy_request = false;
  };
  bool high_res_required = false;
  State layer_before;
  State layer_between;
  State layer_after;
  DrawResult expected_result;

  explicit PrepareToDrawSuccessTestCase(DrawResult result)
      : expected_result(result) {}
};

TEST_F(LayerTreeHostImplTest, PrepareToDrawSucceedsAndFails) {
  std::vector<PrepareToDrawSuccessTestCase> cases;

  // 0. Default case.
  cases.push_back(PrepareToDrawSuccessTestCase(DRAW_SUCCESS));
  // 1. Animated layer first.
  cases.push_back(PrepareToDrawSuccessTestCase(DRAW_SUCCESS));
  cases.back().layer_before.is_animating = true;
  // 2. Animated layer between.
  cases.push_back(PrepareToDrawSuccessTestCase(DRAW_SUCCESS));
  cases.back().layer_between.is_animating = true;
  // 3. Animated layer last.
  cases.push_back(PrepareToDrawSuccessTestCase(DRAW_SUCCESS));
  cases.back().layer_after.is_animating = true;
  // 4. Missing tile first.
  cases.push_back(PrepareToDrawSuccessTestCase(DRAW_SUCCESS));
  cases.back().layer_before.has_missing_tile = true;
  // 5. Missing tile between.
  cases.push_back(PrepareToDrawSuccessTestCase(DRAW_SUCCESS));
  cases.back().layer_between.has_missing_tile = true;
  // 6. Missing tile last.
  cases.push_back(PrepareToDrawSuccessTestCase(DRAW_SUCCESS));
  cases.back().layer_after.has_missing_tile = true;
  // 7. Incomplete tile first.
  cases.push_back(PrepareToDrawSuccessTestCase(DRAW_SUCCESS));
  cases.back().layer_before.has_incomplete_tile = true;
  // 8. Incomplete tile between.
  cases.push_back(PrepareToDrawSuccessTestCase(DRAW_SUCCESS));
  cases.back().layer_between.has_incomplete_tile = true;
  // 9. Incomplete tile last.
  cases.push_back(PrepareToDrawSuccessTestCase(DRAW_SUCCESS));
  cases.back().layer_after.has_incomplete_tile = true;
  // 10. Animation with missing tile.
  cases.push_back(
      PrepareToDrawSuccessTestCase(DRAW_ABORTED_CHECKERBOARD_ANIMATIONS));
  cases.back().layer_between.has_missing_tile = true;
  cases.back().layer_between.is_animating = true;
  // 11. Animation with incomplete tile.
  cases.push_back(PrepareToDrawSuccessTestCase(DRAW_SUCCESS));
  cases.back().layer_between.has_incomplete_tile = true;
  cases.back().layer_between.is_animating = true;

  // 12. High res required.
  cases.push_back(PrepareToDrawSuccessTestCase(DRAW_SUCCESS));
  cases.back().high_res_required = true;
  // 13. High res required with incomplete tile.
  cases.push_back(
      PrepareToDrawSuccessTestCase(DRAW_ABORTED_MISSING_HIGH_RES_CONTENT));
  cases.back().high_res_required = true;
  cases.back().layer_between.has_incomplete_tile = true;
  // 14. High res required with missing tile.
  cases.push_back(
      PrepareToDrawSuccessTestCase(DRAW_ABORTED_MISSING_HIGH_RES_CONTENT));
  cases.back().high_res_required = true;
  cases.back().layer_between.has_missing_tile = true;

  // 15. High res required is higher priority than animating missing tiles.
  cases.push_back(
      PrepareToDrawSuccessTestCase(DRAW_ABORTED_MISSING_HIGH_RES_CONTENT));
  cases.back().high_res_required = true;
  cases.back().layer_between.has_missing_tile = true;
  cases.back().layer_after.has_missing_tile = true;
  cases.back().layer_after.is_animating = true;
  // 16. High res required is higher priority than animating missing tiles.
  cases.push_back(
      PrepareToDrawSuccessTestCase(DRAW_ABORTED_MISSING_HIGH_RES_CONTENT));
  cases.back().high_res_required = true;
  cases.back().layer_between.has_missing_tile = true;
  cases.back().layer_before.has_missing_tile = true;
  cases.back().layer_before.is_animating = true;

  host_impl_->active_tree()->SetRootLayer(
      DidDrawCheckLayer::Create(host_impl_->active_tree(), 1));
  DidDrawCheckLayer* root =
      static_cast<DidDrawCheckLayer*>(host_impl_->active_tree()->root_layer());
  root->SetForceRenderSurface(true);

  LayerTreeHostImpl::FrameData frame;
  SetNeedsRebuildPropertyTrees();
  EXPECT_EQ(DRAW_SUCCESS, PrepareToDrawFrame(&frame));
  host_impl_->DrawLayers(&frame);
  host_impl_->DidDrawAllLayers(frame);
  host_impl_->SwapBuffers(frame);

  for (size_t i = 0; i < cases.size(); ++i) {
    // Clean up host_impl_ state.
    const auto& testcase = cases[i];
    std::vector<LayerImpl*> to_remove;
    for (const auto& child : root->children())
      to_remove.push_back(child.get());
    for (auto* child : to_remove)
      root->RemoveChild(child);
    timeline()->ClearPlayers();

    std::ostringstream scope;
    scope << "Test case: " << i;
    SCOPED_TRACE(scope.str());

    root->AddChild(MissingTextureAnimatingLayer::Create(
        host_impl_->active_tree(), 2, testcase.layer_before.has_missing_tile,
        testcase.layer_before.has_incomplete_tile,
        testcase.layer_before.is_animating, host_impl_->resource_provider(),
        timeline()));
    DidDrawCheckLayer* before =
        static_cast<DidDrawCheckLayer*>(root->children().back().get());
    if (testcase.layer_before.has_copy_request)
      before->AddCopyRequest();

    root->AddChild(MissingTextureAnimatingLayer::Create(
        host_impl_->active_tree(), 3, testcase.layer_between.has_missing_tile,
        testcase.layer_between.has_incomplete_tile,
        testcase.layer_between.is_animating, host_impl_->resource_provider(),
        timeline()));
    DidDrawCheckLayer* between =
        static_cast<DidDrawCheckLayer*>(root->children().back().get());
    if (testcase.layer_between.has_copy_request)
      between->AddCopyRequest();

    root->AddChild(MissingTextureAnimatingLayer::Create(
        host_impl_->active_tree(), 4, testcase.layer_after.has_missing_tile,
        testcase.layer_after.has_incomplete_tile,
        testcase.layer_after.is_animating, host_impl_->resource_provider(),
        timeline()));
    DidDrawCheckLayer* after =
        static_cast<DidDrawCheckLayer*>(root->children().back().get());
    if (testcase.layer_after.has_copy_request)
      after->AddCopyRequest();

    if (testcase.high_res_required)
      host_impl_->SetRequiresHighResToDraw();

    LayerTreeHostImpl::FrameData frame;
    SetNeedsRebuildPropertyTrees();
    EXPECT_EQ(testcase.expected_result, PrepareToDrawFrame(&frame));
    host_impl_->DrawLayers(&frame);
    host_impl_->DidDrawAllLayers(frame);
    host_impl_->SwapBuffers(frame);
  }
}

TEST_F(LayerTreeHostImplTest,
       PrepareToDrawWhenDrawAndSwapFullViewportEveryFrame) {
  CreateHostImpl(DefaultSettings(),
                 FakeOutputSurface::CreateSoftware(
                     make_scoped_ptr(new SoftwareOutputDevice())));

  const gfx::Transform external_transform;
  const gfx::Rect external_viewport;
  const gfx::Rect external_clip;
  const bool resourceless_software_draw = true;
  host_impl_->SetExternalTilePriorityConstraints(external_viewport,
                                                 external_transform);

  std::vector<PrepareToDrawSuccessTestCase> cases;

  // 0. Default case.
  cases.push_back(PrepareToDrawSuccessTestCase(DRAW_SUCCESS));
  // 1. Animation with missing tile.
  cases.push_back(PrepareToDrawSuccessTestCase(DRAW_SUCCESS));
  cases.back().layer_between.has_missing_tile = true;
  cases.back().layer_between.is_animating = true;
  // 2. High res required with incomplete tile.
  cases.push_back(PrepareToDrawSuccessTestCase(DRAW_SUCCESS));
  cases.back().high_res_required = true;
  cases.back().layer_between.has_incomplete_tile = true;
  // 3. High res required with missing tile.
  cases.push_back(PrepareToDrawSuccessTestCase(DRAW_SUCCESS));
  cases.back().high_res_required = true;
  cases.back().layer_between.has_missing_tile = true;

  host_impl_->active_tree()->SetRootLayer(
      DidDrawCheckLayer::Create(host_impl_->active_tree(), 1));
  DidDrawCheckLayer* root =
      static_cast<DidDrawCheckLayer*>(host_impl_->active_tree()->root_layer());
  root->SetForceRenderSurface(true);

  SetNeedsRebuildPropertyTrees();
  host_impl_->OnDraw(external_transform, external_viewport, external_clip,
                     resourceless_software_draw);

  for (size_t i = 0; i < cases.size(); ++i) {
    const auto& testcase = cases[i];
    std::vector<LayerImpl*> to_remove;
    for (const auto& child : root->children())
      to_remove.push_back(child.get());
    for (auto* child : to_remove)
      root->RemoveChild(child);

    std::ostringstream scope;
    scope << "Test case: " << i;
    SCOPED_TRACE(scope.str());

    root->AddChild(MissingTextureAnimatingLayer::Create(
        host_impl_->active_tree(), 2, testcase.layer_before.has_missing_tile,
        testcase.layer_before.has_incomplete_tile,
        testcase.layer_before.is_animating, host_impl_->resource_provider(),
        timeline()));
    DidDrawCheckLayer* before =
        static_cast<DidDrawCheckLayer*>(root->children().back().get());
    if (testcase.layer_before.has_copy_request)
      before->AddCopyRequest();

    root->AddChild(MissingTextureAnimatingLayer::Create(
        host_impl_->active_tree(), 3, testcase.layer_between.has_missing_tile,
        testcase.layer_between.has_incomplete_tile,
        testcase.layer_between.is_animating, host_impl_->resource_provider(),
        timeline()));
    DidDrawCheckLayer* between =
        static_cast<DidDrawCheckLayer*>(root->children().back().get());
    if (testcase.layer_between.has_copy_request)
      between->AddCopyRequest();

    root->AddChild(MissingTextureAnimatingLayer::Create(
        host_impl_->active_tree(), 4, testcase.layer_after.has_missing_tile,
        testcase.layer_after.has_incomplete_tile,
        testcase.layer_after.is_animating, host_impl_->resource_provider(),
        timeline()));
    DidDrawCheckLayer* after =
        static_cast<DidDrawCheckLayer*>(root->children().back().get());
    if (testcase.layer_after.has_copy_request)
      after->AddCopyRequest();

    if (testcase.high_res_required)
      host_impl_->SetRequiresHighResToDraw();

    SetNeedsRebuildPropertyTrees();
    host_impl_->OnDraw(external_transform, external_viewport, external_clip,
                       resourceless_software_draw);
  }
}

TEST_F(LayerTreeHostImplTest, ScrollRootIgnored) {
  scoped_ptr<LayerImpl> root = LayerImpl::Create(host_impl_->active_tree(), 1);
  root->SetScrollClipLayer(Layer::INVALID_ID);
  root->SetForceRenderSurface(true);
  host_impl_->active_tree()->SetRootLayer(std::move(root));
  SetNeedsRebuildPropertyTrees();
  DrawFrame();

  // Scroll event is ignored because layer is not scrollable.
  InputHandler::ScrollStatus status = host_impl_->ScrollBegin(
      BeginState(gfx::Point()).get(), InputHandler::WHEEL);
  EXPECT_EQ(InputHandler::SCROLL_IGNORED, status.thread);
  EXPECT_EQ(MainThreadScrollingReason::kNoScrollingLayer,
            status.main_thread_scrolling_reasons);
  EXPECT_FALSE(did_request_redraw_);
  EXPECT_FALSE(did_request_commit_);
}

TEST_F(LayerTreeHostImplTest, ClampingAfterActivation) {
  host_impl_->CreatePendingTree();
  host_impl_->pending_tree()->PushPageScaleFromMainThread(1.f, 1.f, 1.f);
  CreateScrollAndContentsLayers(host_impl_->pending_tree(),
                                gfx::Size(100, 100));
  host_impl_->pending_tree()->BuildPropertyTreesForTesting();
  host_impl_->ActivateSyncTree();

  host_impl_->CreatePendingTree();
  const gfx::ScrollOffset pending_scroll = gfx::ScrollOffset(-100, -100);
  LayerImpl* active_outer_layer =
      host_impl_->active_tree()->OuterViewportScrollLayer();
  LayerImpl* pending_outer_layer =
      host_impl_->pending_tree()->OuterViewportScrollLayer();
  pending_outer_layer->layer_tree_impl()
      ->property_trees()
      ->scroll_tree.UpdateScrollOffsetBaseForTesting(pending_outer_layer->id(),
                                                     pending_scroll);

  host_impl_->ActivateSyncTree();
  // Scrolloffsets on the active tree will be clamped after activation.
  EXPECT_EQ(active_outer_layer->CurrentScrollOffset(), gfx::ScrollOffset(0, 0));
}

class LayerTreeHostImplTopControlsTest : public LayerTreeHostImplTest {
 public:
  LayerTreeHostImplTopControlsTest()
      // Make the clip size the same as the layer (content) size so the layer is
      // non-scrollable.
      : layer_size_(10, 10),
        clip_size_(layer_size_),
        top_controls_height_(50) {
    viewport_size_ = gfx::Size(clip_size_.width(),
                               clip_size_.height() + top_controls_height_);
  }

  bool CreateHostImpl(const LayerTreeSettings& settings,
                      scoped_ptr<OutputSurface> output_surface) override {
    bool init = LayerTreeHostImplTest::CreateHostImpl(
        settings, std::move(output_surface));
    if (init) {
      host_impl_->active_tree()->set_top_controls_height(top_controls_height_);
      host_impl_->active_tree()->SetCurrentTopControlsShownRatio(1.f);
      host_impl_->active_tree()->PushPageScaleFromMainThread(1.f, 1.f, 1.f);
    }
    return init;
  }

  void SetupTopControlsAndScrollLayerWithVirtualViewport(
      const gfx::Size& inner_viewport_size,
      const gfx::Size& outer_viewport_size,
      const gfx::Size& scroll_layer_size) {
    settings_ = DefaultSettings();
    CreateHostImpl(settings_, CreateOutputSurface());
    host_impl_->sync_tree()->set_top_controls_shrink_blink_size(true);
    host_impl_->sync_tree()->set_top_controls_height(top_controls_height_);
    host_impl_->DidChangeTopControlsPosition();

    scoped_ptr<LayerImpl> root =
        LayerImpl::Create(host_impl_->active_tree(), 1);
    scoped_ptr<LayerImpl> root_clip =
        LayerImpl::Create(host_impl_->active_tree(), 2);
    scoped_ptr<LayerImpl> page_scale =
        LayerImpl::Create(host_impl_->active_tree(), 3);

    scoped_ptr<LayerImpl> outer_scroll =
        LayerImpl::Create(host_impl_->active_tree(), 4);
    scoped_ptr<LayerImpl> outer_clip =
        LayerImpl::Create(host_impl_->active_tree(), 5);

    root_clip->SetBounds(inner_viewport_size);
    root->SetScrollClipLayer(root_clip->id());
    root->SetBounds(outer_viewport_size);
    root->SetPosition(gfx::PointF());
    root->SetDrawsContent(false);
    root->SetIsContainerForFixedPositionLayers(true);
    root_clip->SetForceRenderSurface(true);
    outer_clip->SetBounds(outer_viewport_size);
    outer_scroll->SetScrollClipLayer(outer_clip->id());
    outer_scroll->SetBounds(scroll_layer_size);
    outer_scroll->SetPosition(gfx::PointF());
    outer_scroll->SetDrawsContent(false);
    outer_scroll->SetIsContainerForFixedPositionLayers(true);

    int inner_viewport_scroll_layer_id = root->id();
    int outer_viewport_scroll_layer_id = outer_scroll->id();
    int page_scale_layer_id = page_scale->id();

    outer_clip->AddChild(std::move(outer_scroll));
    root->AddChild(std::move(outer_clip));
    page_scale->AddChild(std::move(root));
    root_clip->AddChild(std::move(page_scale));

    host_impl_->active_tree()->SetRootLayer(std::move(root_clip));
    host_impl_->active_tree()->SetViewportLayersFromIds(
        Layer::INVALID_ID, page_scale_layer_id, inner_viewport_scroll_layer_id,
        outer_viewport_scroll_layer_id);
    host_impl_->active_tree()->BuildPropertyTreesForTesting();

    host_impl_->SetViewportSize(inner_viewport_size);
    LayerImpl* root_clip_ptr = host_impl_->active_tree()->root_layer();
    EXPECT_EQ(inner_viewport_size, root_clip_ptr->bounds());
  }

 protected:
  gfx::Size layer_size_;
  gfx::Size clip_size_;
  gfx::Size viewport_size_;
  float top_controls_height_;

  LayerTreeSettings settings_;
};  // class LayerTreeHostImplTopControlsTest

// Tests that, on a page with content the same size as the viewport, hiding
// the top controls also increases the ScrollableSize (i.e. the content size).
// Since the viewport got larger, the effective scrollable "content" also did.
// This ensures, for one thing, that the overscroll glow is shown in the right
// place.
TEST_F(LayerTreeHostImplTopControlsTest,
    HidingTopControlsExpandsScrollableSize) {
  SetupTopControlsAndScrollLayerWithVirtualViewport(
      gfx::Size(50, 50), gfx::Size(50, 50), gfx::Size(50, 50));

  LayerTreeImpl* active_tree = host_impl_->active_tree();

  // Create a content layer beneath the outer viewport scroll layer.
  int id = host_impl_->OuterViewportScrollLayer()->id();
  host_impl_->OuterViewportScrollLayer()->AddChild(
      LayerImpl::Create(host_impl_->active_tree(), id + 2));
  LayerImpl* content =
      active_tree->OuterViewportScrollLayer()->children()[0].get();
  content->SetBounds(gfx::Size(50, 50));

  SetNeedsRebuildPropertyTrees();
  DrawFrame();

  LayerImpl* inner_container = active_tree->InnerViewportContainerLayer();
  LayerImpl* outer_container = active_tree->OuterViewportContainerLayer();

  // The top controls should start off showing so the viewport should be shrunk.
  ASSERT_EQ(gfx::Size(50, 50), inner_container->bounds());
  ASSERT_EQ(gfx::Size(50, 50), outer_container->bounds());

  EXPECT_EQ(gfx::SizeF(50, 50), active_tree->ScrollableSize());

  EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
            host_impl_
                ->ScrollBegin(BeginState(gfx::Point()).get(),
                              InputHandler::TOUCHSCREEN)
                .thread);

  host_impl_->top_controls_manager()->ScrollBegin();

  // Hide the top controls by a bit, the scrollable size should increase but the
  // actual content bounds shouldn't.
  {
    host_impl_->top_controls_manager()->ScrollBy(gfx::Vector2dF(0.f, 25.f));
    ASSERT_EQ(gfx::Size(50, 75), inner_container->bounds());
    ASSERT_EQ(gfx::Size(50, 75), outer_container->bounds());
    EXPECT_EQ(gfx::SizeF(50, 75), active_tree->ScrollableSize());
    EXPECT_EQ(gfx::SizeF(50, 50), content->BoundsForScrolling());
  }

  // Fully hide the top controls.
  {
    host_impl_->top_controls_manager()->ScrollBy(gfx::Vector2dF(0.f, 25.f));
    ASSERT_EQ(gfx::Size(50, 100), inner_container->bounds());
    ASSERT_EQ(gfx::Size(50, 100), outer_container->bounds());
    EXPECT_EQ(gfx::SizeF(50, 100), active_tree->ScrollableSize());
    EXPECT_EQ(gfx::SizeF(50, 50), content->BoundsForScrolling());
  }

  // Scrolling additionally shouldn't have any effect.
  {
    host_impl_->top_controls_manager()->ScrollBy(gfx::Vector2dF(0.f, 25.f));
    ASSERT_EQ(gfx::Size(50, 100), inner_container->bounds());
    ASSERT_EQ(gfx::Size(50, 100), outer_container->bounds());
    EXPECT_EQ(gfx::SizeF(50, 100), active_tree->ScrollableSize());
    EXPECT_EQ(gfx::SizeF(50, 50), content->BoundsForScrolling());
  }

  host_impl_->top_controls_manager()->ScrollEnd();
  host_impl_->ScrollEnd(EndState().get());
}

TEST_F(LayerTreeHostImplTopControlsTest, ScrollTopControlsByFractionalAmount) {
  SetupTopControlsAndScrollLayerWithVirtualViewport(
      gfx::Size(10, 10), gfx::Size(10, 10), gfx::Size(10, 10));
  DrawFrame();

  EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
            host_impl_
                ->ScrollBegin(BeginState(gfx::Point()).get(),
                              InputHandler::TOUCHSCREEN)
                .thread);

  // Make the test scroll delta a fractional amount, to verify that the
  // fixed container size delta is (1) non-zero, and (2) fractional, and
  // (3) matches the movement of the top controls.
  gfx::Vector2dF top_controls_scroll_delta(0.f, 5.25f);
  host_impl_->top_controls_manager()->ScrollBegin();
  host_impl_->top_controls_manager()->ScrollBy(top_controls_scroll_delta);
  host_impl_->top_controls_manager()->ScrollEnd();

  LayerImpl* inner_viewport_scroll_layer =
      host_impl_->active_tree()->InnerViewportScrollLayer();
  DCHECK(inner_viewport_scroll_layer);
  host_impl_->ScrollEnd(EndState().get());
  EXPECT_FLOAT_EQ(top_controls_scroll_delta.y(),
                  inner_viewport_scroll_layer->FixedContainerSizeDelta().y());
}

// In this test, the outer viewport is initially unscrollable. We test that a
// scroll initiated on the inner viewport, causing the top controls to show and
// thus making the outer viewport scrollable, still scrolls the outer viewport.
TEST_F(LayerTreeHostImplTopControlsTest,
    TopControlsOuterViewportBecomesScrollable) {
  SetupTopControlsAndScrollLayerWithVirtualViewport(
      gfx::Size(10, 50), gfx::Size(10, 50), gfx::Size(10, 100));
  DrawFrame();

  LayerImpl* inner_scroll =
      host_impl_->active_tree()->InnerViewportScrollLayer();
  inner_scroll->SetDrawsContent(true);
  LayerImpl* inner_container =
      host_impl_->active_tree()->InnerViewportContainerLayer();
  LayerImpl* outer_scroll =
      host_impl_->active_tree()->OuterViewportScrollLayer();
  outer_scroll->SetDrawsContent(true);
  LayerImpl* outer_container =
      host_impl_->active_tree()->OuterViewportContainerLayer();

  // Need SetDrawsContent so ScrollBegin's hit test finds an actual layer.
  outer_scroll->SetDrawsContent(true);
  host_impl_->active_tree()->PushPageScaleFromMainThread(2.f, 1.f, 2.f);

  EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
            host_impl_
                ->ScrollBegin(BeginState(gfx::Point()).get(),
                              InputHandler::TOUCHSCREEN)
                .thread);
  host_impl_->ScrollBy(
      UpdateState(gfx::Point(), gfx::Vector2dF(0.f, 50.f)).get());

  // The entire scroll delta should have been used to hide the top controls.
  // The viewport layers should be resized back to their full sizes.
  EXPECT_EQ(0.f, host_impl_->active_tree()->CurrentTopControlsShownRatio());
  EXPECT_EQ(0.f, inner_scroll->CurrentScrollOffset().y());
  EXPECT_EQ(100.f, inner_container->BoundsForScrolling().height());
  EXPECT_EQ(100.f, outer_container->BoundsForScrolling().height());

  // The inner viewport should be scrollable by 50px * page_scale.
  host_impl_->ScrollBy(
      UpdateState(gfx::Point(), gfx::Vector2dF(0.f, 100.f)).get());
  EXPECT_EQ(50.f, inner_scroll->CurrentScrollOffset().y());
  EXPECT_EQ(0.f, outer_scroll->CurrentScrollOffset().y());
  EXPECT_EQ(gfx::ScrollOffset(), outer_scroll->MaxScrollOffset());

  host_impl_->ScrollEnd(EndState().get());

  EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
            host_impl_
                ->ScrollBegin(BeginState(gfx::Point()).get(),
                              InputHandler::TOUCHSCREEN)
                .thread);
  EXPECT_EQ(host_impl_->CurrentlyScrollingLayer(), inner_scroll);

  host_impl_->ScrollBy(
      UpdateState(gfx::Point(), gfx::Vector2dF(0.f, -50.f)).get());

  // The entire scroll delta should have been used to show the top controls.
  // The outer viewport should be resized to accomodate and scrolled to the
  // bottom of the document to keep the viewport in place.
  EXPECT_EQ(1.f, host_impl_->active_tree()->CurrentTopControlsShownRatio());
  EXPECT_EQ(50.f, outer_container->BoundsForScrolling().height());
  EXPECT_EQ(50.f, inner_container->BoundsForScrolling().height());
  EXPECT_EQ(25.f, outer_scroll->CurrentScrollOffset().y());
  EXPECT_EQ(25.f, inner_scroll->CurrentScrollOffset().y());

  // Now when we continue scrolling, make sure the outer viewport gets scrolled
  // since it wasn't scrollable when the scroll began.
  host_impl_->ScrollBy(
      UpdateState(gfx::Point(), gfx::Vector2dF(0.f, -20.f)).get());
  EXPECT_EQ(25.f, outer_scroll->CurrentScrollOffset().y());
  EXPECT_EQ(15.f, inner_scroll->CurrentScrollOffset().y());

  host_impl_->ScrollBy(
      UpdateState(gfx::Point(), gfx::Vector2dF(0.f, -30.f)).get());
  EXPECT_EQ(25.f, outer_scroll->CurrentScrollOffset().y());
  EXPECT_EQ(0.f, inner_scroll->CurrentScrollOffset().y());

  host_impl_->ScrollBy(
      UpdateState(gfx::Point(), gfx::Vector2dF(0.f, -50.f)).get());
  host_impl_->ScrollEnd(EndState().get());

  EXPECT_EQ(0.f, outer_scroll->CurrentScrollOffset().y());
  EXPECT_EQ(0.f, inner_scroll->CurrentScrollOffset().y());
}

// Test that the fixed position container delta is appropriately adjusted
// by the top controls showing/hiding and page scale doesn't affect it.
TEST_F(LayerTreeHostImplTopControlsTest, FixedContainerDelta) {
  SetupTopControlsAndScrollLayerWithVirtualViewport(
      gfx::Size(100, 100), gfx::Size(100, 100), gfx::Size(100, 100));
  DrawFrame();
  host_impl_->active_tree()->PushPageScaleFromMainThread(1.f, 1.f, 2.f);

  float page_scale = 1.5f;
  LayerImpl* outer_viewport_scroll_layer =
      host_impl_->active_tree()->OuterViewportScrollLayer();

  // Zoom in, since the fixed container is the outer viewport, the delta should
  // not be scaled.
  host_impl_->active_tree()->PushPageScaleFromMainThread(page_scale, 1.f, 2.f);

  EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
            host_impl_
                ->ScrollBegin(BeginState(gfx::Point()).get(),
                              InputHandler::TOUCHSCREEN)
                .thread);

  // Scroll down, the top controls hiding should expand the viewport size so
  // the delta should be equal to the scroll distance.
  gfx::Vector2dF top_controls_scroll_delta(0.f, 20.f);
  host_impl_->top_controls_manager()->ScrollBegin();
  host_impl_->top_controls_manager()->ScrollBy(top_controls_scroll_delta);
  EXPECT_FLOAT_EQ(top_controls_height_ - top_controls_scroll_delta.y(),
                  host_impl_->top_controls_manager()->ContentTopOffset());
  EXPECT_FLOAT_EQ(top_controls_scroll_delta.y(),
                  outer_viewport_scroll_layer->FixedContainerSizeDelta().y());
  host_impl_->ScrollEnd(EndState().get());

  // Scroll past the maximum extent. The delta shouldn't be greater than the
  // top controls height.
  host_impl_->top_controls_manager()->ScrollBegin();
  host_impl_->top_controls_manager()->ScrollBy(top_controls_scroll_delta);
  host_impl_->top_controls_manager()->ScrollBy(top_controls_scroll_delta);
  host_impl_->top_controls_manager()->ScrollBy(top_controls_scroll_delta);
  EXPECT_EQ(0.f, host_impl_->top_controls_manager()->ContentTopOffset());
  EXPECT_VECTOR_EQ(gfx::Vector2dF(0, top_controls_height_),
                   outer_viewport_scroll_layer->FixedContainerSizeDelta());
  host_impl_->ScrollEnd(EndState().get());

  // Scroll in the direction to make the top controls show.
  host_impl_->top_controls_manager()->ScrollBegin();
  host_impl_->top_controls_manager()->ScrollBy(-top_controls_scroll_delta);
  EXPECT_EQ(top_controls_scroll_delta.y(),
            host_impl_->top_controls_manager()->ContentTopOffset());
  EXPECT_VECTOR_EQ(
      gfx::Vector2dF(0, top_controls_height_ - top_controls_scroll_delta.y()),
      outer_viewport_scroll_layer->FixedContainerSizeDelta());
  host_impl_->top_controls_manager()->ScrollEnd();
}

// Test that if only the top controls are scrolled, we shouldn't request a
// commit.
TEST_F(LayerTreeHostImplTopControlsTest, TopControlsDontTriggerCommit) {
  SetupTopControlsAndScrollLayerWithVirtualViewport(
      gfx::Size(100, 50), gfx::Size(100, 100), gfx::Size(100, 100));
  DrawFrame();

  // Show top controls
  EXPECT_EQ(1.f, host_impl_->active_tree()->CurrentTopControlsShownRatio());

  // Scroll 25px to hide top controls
  gfx::Vector2dF scroll_delta(0.f, 25.f);
  EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
            host_impl_
                ->ScrollBegin(BeginState(gfx::Point()).get(),
                              InputHandler::TOUCHSCREEN)
                .thread);
  host_impl_->ScrollBy(UpdateState(gfx::Point(), scroll_delta).get());
  EXPECT_FALSE(did_request_commit_);
}

// Test that if a scrollable sublayer doesn't consume the scroll,
// top controls should hide when scrolling down.
TEST_F(LayerTreeHostImplTopControlsTest, TopControlsScrollableSublayer) {
  gfx::Size sub_content_size(100, 400);
  gfx::Size sub_content_layer_size(100, 300);
  SetupTopControlsAndScrollLayerWithVirtualViewport(
      gfx::Size(100, 50), gfx::Size(100, 100), gfx::Size(100, 100));
  DrawFrame();

  // Show top controls
  EXPECT_EQ(1.f, host_impl_->active_tree()->CurrentTopControlsShownRatio());

  LayerImpl* outer_viewport_scroll_layer =
      host_impl_->active_tree()->OuterViewportScrollLayer();
  int id = outer_viewport_scroll_layer->id();

  scoped_ptr<LayerImpl> child =
      LayerImpl::Create(host_impl_->active_tree(), id + 2);
  scoped_ptr<LayerImpl> child_clip =
      LayerImpl::Create(host_impl_->active_tree(), id + 3);

  child_clip->SetBounds(sub_content_layer_size);
  child->SetScrollClipLayer(child_clip->id());
  child->SetBounds(sub_content_size);
  child->SetPosition(gfx::PointF());
  child->SetDrawsContent(true);
  child->SetIsContainerForFixedPositionLayers(true);

  // scroll child to limit
  SetScrollOffsetDelta(child.get(), gfx::Vector2dF(0, 100.f));
  child_clip->AddChild(std::move(child));
  outer_viewport_scroll_layer->AddChild(std::move(child_clip));

  // Scroll 25px to hide top controls
  gfx::Vector2dF scroll_delta(0.f, 25.f);
  host_impl_->active_tree()->property_trees()->needs_rebuild = true;
  host_impl_->active_tree()->BuildPropertyTreesForTesting();
  EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
            host_impl_
                ->ScrollBegin(BeginState(gfx::Point()).get(),
                              InputHandler::TOUCHSCREEN)
                .thread);
  host_impl_->ScrollBy(UpdateState(gfx::Point(), scroll_delta).get());
  host_impl_->ScrollEnd(EndState().get());

  // Top controls should be hidden
  EXPECT_EQ(scroll_delta.y(),
            top_controls_height_ -
                host_impl_->top_controls_manager()->ContentTopOffset());
}

// Ensure setting the top controls position explicitly using the setters on the
// TreeImpl correctly affects the top controls manager and viewport bounds.
TEST_F(LayerTreeHostImplTopControlsTest, PositionTopControlsExplicitly) {
  settings_ = DefaultSettings();
  CreateHostImpl(settings_, CreateOutputSurface());
  SetupTopControlsAndScrollLayerWithVirtualViewport(
      layer_size_, layer_size_, layer_size_);
  DrawFrame();

  host_impl_->active_tree()->SetCurrentTopControlsShownRatio(0.f);
  host_impl_->active_tree()->top_controls_shown_ratio()->PushFromMainThread(
      30.f / top_controls_height_);
  host_impl_->active_tree()->top_controls_shown_ratio()->PushPendingToActive();
  EXPECT_FLOAT_EQ(30.f, host_impl_->top_controls_manager()->ContentTopOffset());
  EXPECT_FLOAT_EQ(-20.f,
                  host_impl_->top_controls_manager()->ControlsTopOffset());

  host_impl_->active_tree()->SetCurrentTopControlsShownRatio(0.f);
  EXPECT_FLOAT_EQ(0.f, host_impl_->top_controls_manager()->ContentTopOffset());
  EXPECT_FLOAT_EQ(-50.f,
                  host_impl_->top_controls_manager()->ControlsTopOffset());

  host_impl_->DidChangeTopControlsPosition();

  // Now that top controls have moved, expect the clip to resize.
  LayerImpl* inner_clip_ptr =
      host_impl_->InnerViewportScrollLayer()->parent()->parent();
  EXPECT_EQ(viewport_size_, inner_clip_ptr->bounds());
}

// Test that the top_controls delta and sent delta are appropriately
// applied on sync tree activation. The total top controls offset shouldn't
// change after the activation.
TEST_F(LayerTreeHostImplTopControlsTest, ApplyDeltaOnTreeActivation) {
  settings_ = DefaultSettings();
  CreateHostImpl(settings_, CreateOutputSurface());
  SetupTopControlsAndScrollLayerWithVirtualViewport(
      layer_size_, layer_size_, layer_size_);
  DrawFrame();

  host_impl_->active_tree()->top_controls_shown_ratio()->PushFromMainThread(
      20.f / top_controls_height_);
  host_impl_->active_tree()->top_controls_shown_ratio()->PushPendingToActive();
  host_impl_->active_tree()->SetCurrentTopControlsShownRatio(
      15.f / top_controls_height_);
  host_impl_->active_tree()
      ->top_controls_shown_ratio()
      ->PullDeltaForMainThread();
  host_impl_->active_tree()->SetCurrentTopControlsShownRatio(0.f);
  host_impl_->sync_tree()->PushTopControlsFromMainThread(15.f /
                                                         top_controls_height_);

  host_impl_->DidChangeTopControlsPosition();
  LayerImpl* inner_clip_ptr =
      host_impl_->InnerViewportScrollLayer()->parent()->parent();
  EXPECT_EQ(viewport_size_, inner_clip_ptr->bounds());
  EXPECT_EQ(0.f, host_impl_->top_controls_manager()->ContentTopOffset());

  host_impl_->ActivateSyncTree();

  inner_clip_ptr = host_impl_->InnerViewportScrollLayer()->parent()->parent();
  EXPECT_EQ(0.f, host_impl_->top_controls_manager()->ContentTopOffset());
  EXPECT_EQ(viewport_size_, inner_clip_ptr->bounds());

  EXPECT_FLOAT_EQ(
      -15.f, host_impl_->active_tree()->top_controls_shown_ratio()->Delta() *
                 top_controls_height_);
  EXPECT_FLOAT_EQ(
      15.f,
      host_impl_->active_tree()->top_controls_shown_ratio()->ActiveBase() *
          top_controls_height_);
}

// Test that changing the top controls layout height is correctly applied to
// the inner viewport container bounds. That is, the top controls layout
// height is the amount that the inner viewport container was shrunk outside
// the compositor to accommodate the top controls.
TEST_F(LayerTreeHostImplTopControlsTest, TopControlsLayoutHeightChanged) {
  settings_ = DefaultSettings();
  CreateHostImpl(settings_, CreateOutputSurface());
  SetupTopControlsAndScrollLayerWithVirtualViewport(
      layer_size_, layer_size_, layer_size_);
  DrawFrame();

  host_impl_->sync_tree()->PushTopControlsFromMainThread(1.f);
  host_impl_->sync_tree()->set_top_controls_shrink_blink_size(true);

  host_impl_->active_tree()->top_controls_shown_ratio()->PushFromMainThread(
      1.f);
  host_impl_->active_tree()->top_controls_shown_ratio()->PushPendingToActive();
  host_impl_->active_tree()->SetCurrentTopControlsShownRatio(0.f);

  host_impl_->DidChangeTopControlsPosition();
  LayerImpl* inner_clip_ptr =
      host_impl_->InnerViewportScrollLayer()->parent()->parent();
  EXPECT_EQ(viewport_size_, inner_clip_ptr->bounds());
  EXPECT_EQ(0.f, host_impl_->top_controls_manager()->ContentTopOffset());

  host_impl_->sync_tree()->root_layer()->SetBounds(
      gfx::Size(inner_clip_ptr->bounds().width(),
                inner_clip_ptr->bounds().height() - 50.f));

  host_impl_->ActivateSyncTree();

  inner_clip_ptr =
      host_impl_->InnerViewportScrollLayer()->parent()->parent();
  EXPECT_EQ(0.f, host_impl_->top_controls_manager()->ContentTopOffset());

  // The total bounds should remain unchanged since the bounds delta should
  // account for the difference between the layout height and the current
  // top controls offset.
  EXPECT_EQ(viewport_size_, inner_clip_ptr->bounds());
  EXPECT_VECTOR_EQ(gfx::Vector2dF(0.f, 50.f), inner_clip_ptr->bounds_delta());

  host_impl_->active_tree()->SetCurrentTopControlsShownRatio(1.f);
  host_impl_->DidChangeTopControlsPosition();

  EXPECT_EQ(1.f, host_impl_->top_controls_manager()->TopControlsShownRatio());
  EXPECT_EQ(50.f, host_impl_->top_controls_manager()->TopControlsHeight());
  EXPECT_EQ(50.f, host_impl_->top_controls_manager()->ContentTopOffset());
  EXPECT_VECTOR_EQ(gfx::Vector2dF(0.f, 0.f), inner_clip_ptr->bounds_delta());
  EXPECT_EQ(gfx::Size(viewport_size_.width(), viewport_size_.height() - 50.f),
            inner_clip_ptr->bounds());
}

// Test that showing/hiding the top controls when the viewport is fully scrolled
// doesn't incorrectly change the viewport offset due to clamping from changing
// viewport bounds.
TEST_F(LayerTreeHostImplTopControlsTest, TopControlsViewportOffsetClamping) {
  SetupTopControlsAndScrollLayerWithVirtualViewport(
      gfx::Size(100, 100), gfx::Size(200, 200), gfx::Size(200, 400));
  DrawFrame();

  EXPECT_EQ(1.f, host_impl_->active_tree()->CurrentTopControlsShownRatio());

  LayerImpl* outer_scroll = host_impl_->OuterViewportScrollLayer();
  LayerImpl* inner_scroll = host_impl_->InnerViewportScrollLayer();

  // Scroll the viewports to max scroll offset.
  SetScrollOffsetDelta(outer_scroll, gfx::Vector2dF(0, 200.f));
  SetScrollOffsetDelta(inner_scroll, gfx::Vector2dF(100, 100.f));

  gfx::ScrollOffset viewport_offset =
      host_impl_->active_tree()->TotalScrollOffset();
  EXPECT_EQ(host_impl_->active_tree()->TotalMaxScrollOffset(), viewport_offset);

  // Hide the top controls by 25px.
  gfx::Vector2dF scroll_delta(0.f, 25.f);
  EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
            host_impl_
                ->ScrollBegin(BeginState(gfx::Point()).get(),
                              InputHandler::TOUCHSCREEN)
                .thread);
  host_impl_->ScrollBy(UpdateState(gfx::Point(), scroll_delta).get());

  // scrolling down at the max extents no longer hides the top controls
  EXPECT_EQ(1.f, host_impl_->active_tree()->CurrentTopControlsShownRatio());

  // forcefully hide the top controls by 25px
  host_impl_->top_controls_manager()->ScrollBy(scroll_delta);
  host_impl_->ScrollEnd(EndState().get());

  EXPECT_FLOAT_EQ(scroll_delta.y(),
                  top_controls_height_ -
                      host_impl_->top_controls_manager()->ContentTopOffset());

  inner_scroll->ClampScrollToMaxScrollOffset();
  outer_scroll->ClampScrollToMaxScrollOffset();

  // We should still be fully scrolled.
  EXPECT_EQ(host_impl_->active_tree()->TotalMaxScrollOffset(),
            host_impl_->active_tree()->TotalScrollOffset());

  viewport_offset = host_impl_->active_tree()->TotalScrollOffset();

  // Bring the top controls down by 25px.
  scroll_delta = gfx::Vector2dF(0.f, -25.f);
  EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
            host_impl_
                ->ScrollBegin(BeginState(gfx::Point()).get(),
                              InputHandler::TOUCHSCREEN)
                .thread);
  host_impl_->ScrollBy(UpdateState(gfx::Point(), scroll_delta).get());
  host_impl_->ScrollEnd(EndState().get());

  // The viewport offset shouldn't have changed.
  EXPECT_EQ(viewport_offset,
            host_impl_->active_tree()->TotalScrollOffset());

  // Scroll the viewports to max scroll offset.
  SetScrollOffsetDelta(outer_scroll, gfx::Vector2dF(0, 200.f));
  SetScrollOffsetDelta(inner_scroll, gfx::Vector2dF(100, 100.f));
  EXPECT_EQ(host_impl_->active_tree()->TotalMaxScrollOffset(),
            host_impl_->active_tree()->TotalScrollOffset());
}

// Test that the top controls coming in and out maintains the same aspect ratio
// between the inner and outer viewports.
TEST_F(LayerTreeHostImplTopControlsTest, TopControlsAspectRatio) {
  SetupTopControlsAndScrollLayerWithVirtualViewport(
      gfx::Size(100, 100), gfx::Size(200, 200), gfx::Size(200, 400));
  host_impl_->active_tree()->PushPageScaleFromMainThread(1.f, 0.5f, 2.f);
  DrawFrame();

  EXPECT_FLOAT_EQ(top_controls_height_,
                  host_impl_->top_controls_manager()->ContentTopOffset());

  gfx::Vector2dF scroll_delta(0.f, 25.f);
  EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
            host_impl_
                ->ScrollBegin(BeginState(gfx::Point()).get(),
                              InputHandler::TOUCHSCREEN)
                .thread);
  host_impl_->ScrollBy(UpdateState(gfx::Point(), scroll_delta).get());
  host_impl_->ScrollEnd(EndState().get());

  EXPECT_FLOAT_EQ(scroll_delta.y(),
                  top_controls_height_ -
                      host_impl_->top_controls_manager()->ContentTopOffset());

  // Top controls were hidden by 25px so the inner viewport should have expanded
  // by that much.
  LayerImpl* outer_container =
            host_impl_->active_tree()->OuterViewportContainerLayer();
  LayerImpl* inner_container =
            host_impl_->active_tree()->InnerViewportContainerLayer();
  EXPECT_EQ(gfx::SizeF(100.f, 100.f + 25.f),
            inner_container->BoundsForScrolling());

  // Outer viewport should match inner's aspect ratio. The bounds are ceiled.
  float aspect_ratio = inner_container->BoundsForScrolling().width() /
                       inner_container->BoundsForScrolling().height();
  gfx::SizeF expected =
      gfx::SizeF(gfx::ToCeiledSize(gfx::SizeF(200, 200 / aspect_ratio)));
  EXPECT_EQ(expected, outer_container->BoundsForScrolling());
  EXPECT_EQ(expected,
            host_impl_->InnerViewportScrollLayer()->BoundsForScrolling());
}

// Test that scrolling the outer viewport affects the top controls.
TEST_F(LayerTreeHostImplTopControlsTest, TopControlsScrollOuterViewport) {
  SetupTopControlsAndScrollLayerWithVirtualViewport(
      gfx::Size(100, 100), gfx::Size(200, 200), gfx::Size(200, 400));
  DrawFrame();

  EXPECT_EQ(top_controls_height_,
            host_impl_->top_controls_manager()->ContentTopOffset());

  // Send a gesture scroll that will scroll the outer viewport, make sure the
  // top controls get scrolled.
  gfx::Vector2dF scroll_delta(0.f, 15.f);
  EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
            host_impl_
                ->ScrollBegin(BeginState(gfx::Point()).get(),
                              InputHandler::TOUCHSCREEN)
                .thread);
  host_impl_->ScrollBy(UpdateState(gfx::Point(), scroll_delta).get());

  EXPECT_EQ(host_impl_->InnerViewportScrollLayer(),
            host_impl_->CurrentlyScrollingLayer());
  host_impl_->ScrollEnd(EndState().get());

  EXPECT_FLOAT_EQ(scroll_delta.y(),
                  top_controls_height_ -
                      host_impl_->top_controls_manager()->ContentTopOffset());

  scroll_delta = gfx::Vector2dF(0.f, 50.f);
  EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
            host_impl_
                ->ScrollBegin(BeginState(gfx::Point()).get(),
                              InputHandler::TOUCHSCREEN)
                .thread);
  host_impl_->ScrollBy(UpdateState(gfx::Point(), scroll_delta).get());

  EXPECT_EQ(0, host_impl_->top_controls_manager()->ContentTopOffset());
  EXPECT_EQ(host_impl_->InnerViewportScrollLayer(),
            host_impl_->CurrentlyScrollingLayer());

  host_impl_->ScrollEnd(EndState().get());

  // Position the viewports such that the inner viewport will be scrolled.
  gfx::Vector2dF inner_viewport_offset(0.f, 25.f);
  SetScrollOffsetDelta(host_impl_->OuterViewportScrollLayer(),
                       gfx::Vector2dF());
  SetScrollOffsetDelta(host_impl_->InnerViewportScrollLayer(),
                       inner_viewport_offset);

  scroll_delta = gfx::Vector2dF(0.f, -65.f);
  EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
            host_impl_
                ->ScrollBegin(BeginState(gfx::Point()).get(),
                              InputHandler::TOUCHSCREEN)
                .thread);
  host_impl_->ScrollBy(UpdateState(gfx::Point(), scroll_delta).get());

  EXPECT_EQ(top_controls_height_,
            host_impl_->top_controls_manager()->ContentTopOffset());
  EXPECT_FLOAT_EQ(
      inner_viewport_offset.y() + (scroll_delta.y() + top_controls_height_),
      ScrollDelta(host_impl_->InnerViewportScrollLayer()).y());

  host_impl_->ScrollEnd(EndState().get());
}

TEST_F(LayerTreeHostImplTopControlsTest,
       ScrollNonScrollableRootWithTopControls) {
  settings_ = DefaultSettings();
  CreateHostImpl(settings_, CreateOutputSurface());
  SetupTopControlsAndScrollLayerWithVirtualViewport(
      layer_size_, layer_size_, layer_size_);
  DrawFrame();

  EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
            host_impl_
                ->ScrollBegin(BeginState(gfx::Point()).get(),
                              InputHandler::TOUCHSCREEN)
                .thread);

  host_impl_->top_controls_manager()->ScrollBegin();
  host_impl_->top_controls_manager()->ScrollBy(gfx::Vector2dF(0.f, 50.f));
  host_impl_->top_controls_manager()->ScrollEnd();
  EXPECT_EQ(0.f, host_impl_->top_controls_manager()->ContentTopOffset());
  // Now that top controls have moved, expect the clip to resize.
  LayerImpl* inner_clip_ptr =
      host_impl_->InnerViewportScrollLayer()->parent()->parent();
  EXPECT_EQ(viewport_size_, inner_clip_ptr->bounds());

  host_impl_->ScrollEnd(EndState().get());

  EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
            host_impl_
                ->ScrollBegin(BeginState(gfx::Point()).get(),
                              InputHandler::TOUCHSCREEN)
                .thread);

  float scroll_increment_y = -25.f;
  host_impl_->top_controls_manager()->ScrollBegin();
  host_impl_->top_controls_manager()->ScrollBy(
      gfx::Vector2dF(0.f, scroll_increment_y));
  EXPECT_FLOAT_EQ(-scroll_increment_y,
                  host_impl_->top_controls_manager()->ContentTopOffset());
  // Now that top controls have moved, expect the clip to resize.
  EXPECT_EQ(gfx::Size(viewport_size_.width(),
                      viewport_size_.height() + scroll_increment_y),
            inner_clip_ptr->bounds());

  host_impl_->top_controls_manager()->ScrollBy(
      gfx::Vector2dF(0.f, scroll_increment_y));
  host_impl_->top_controls_manager()->ScrollEnd();
  EXPECT_FLOAT_EQ(-2 * scroll_increment_y,
                  host_impl_->top_controls_manager()->ContentTopOffset());
  // Now that top controls have moved, expect the clip to resize.
  EXPECT_EQ(clip_size_, inner_clip_ptr->bounds());

  host_impl_->ScrollEnd(EndState().get());

  // Verify the layer is once-again non-scrollable.
  EXPECT_EQ(
      gfx::ScrollOffset(),
      host_impl_->active_tree()->InnerViewportScrollLayer()->MaxScrollOffset());

  EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
            host_impl_
                ->ScrollBegin(BeginState(gfx::Point()).get(),
                              InputHandler::TOUCHSCREEN)
                .thread);
}

TEST_F(LayerTreeHostImplTest, ScrollNonCompositedRoot) {
  // Test the configuration where a non-composited root layer is embedded in a
  // scrollable outer layer.
  gfx::Size surface_size(10, 10);
  gfx::Size contents_size(20, 20);

  scoped_ptr<LayerImpl> content_layer =
      LayerImpl::Create(host_impl_->active_tree(), 1);
  content_layer->SetDrawsContent(true);
  content_layer->SetPosition(gfx::PointF());
  content_layer->SetBounds(contents_size);

  scoped_ptr<LayerImpl> scroll_clip_layer =
      LayerImpl::Create(host_impl_->active_tree(), 3);
  scroll_clip_layer->SetBounds(surface_size);

  scoped_ptr<LayerImpl> scroll_layer =
      LayerImpl::Create(host_impl_->active_tree(), 2);
  scroll_layer->SetScrollClipLayer(3);
  scroll_layer->SetBounds(contents_size);
  scroll_layer->SetPosition(gfx::PointF());
  scroll_layer->AddChild(std::move(content_layer));
  scroll_clip_layer->AddChild(std::move(scroll_layer));

  scroll_clip_layer->SetForceRenderSurface(true);
  host_impl_->active_tree()->SetRootLayer(std::move(scroll_clip_layer));
  host_impl_->SetViewportSize(surface_size);
  SetNeedsRebuildPropertyTrees();
  DrawFrame();

  EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
            host_impl_->ScrollBegin(BeginState(gfx::Point(5, 5)).get(),
                                    InputHandler::WHEEL)
                .thread);
  host_impl_->ScrollBy(UpdateState(gfx::Point(), gfx::Vector2d(0, 10)).get());
  host_impl_->ScrollEnd(EndState().get());
  EXPECT_TRUE(did_request_redraw_);
  EXPECT_TRUE(did_request_commit_);
}

TEST_F(LayerTreeHostImplTest, ScrollChildCallsCommitAndRedraw) {
  gfx::Size surface_size(10, 10);
  gfx::Size contents_size(20, 20);
  scoped_ptr<LayerImpl> root = LayerImpl::Create(host_impl_->active_tree(), 1);
  root->SetBounds(surface_size);
  root->AddChild(CreateScrollableLayer(2, contents_size, root.get()));
  root->SetForceRenderSurface(true);
  host_impl_->active_tree()->SetRootLayer(std::move(root));
  host_impl_->SetViewportSize(surface_size);
  SetNeedsRebuildPropertyTrees();
  DrawFrame();

  EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
            host_impl_->ScrollBegin(BeginState(gfx::Point(5, 5)).get(),
                                    InputHandler::WHEEL)
                .thread);
  host_impl_->ScrollBy(UpdateState(gfx::Point(), gfx::Vector2d(0, 10)).get());
  host_impl_->ScrollEnd(EndState().get());
  EXPECT_TRUE(did_request_redraw_);
  EXPECT_TRUE(did_request_commit_);
}

TEST_F(LayerTreeHostImplTest, ScrollMissesChild) {
  gfx::Size surface_size(10, 10);
  scoped_ptr<LayerImpl> root = LayerImpl::Create(host_impl_->active_tree(), 1);
  root->AddChild(CreateScrollableLayer(2, surface_size, root.get()));
  root->SetForceRenderSurface(true);
  host_impl_->active_tree()->SetRootLayer(std::move(root));
  host_impl_->SetViewportSize(surface_size);
  SetNeedsRebuildPropertyTrees();
  DrawFrame();

  // Scroll event is ignored because the input coordinate is outside the layer
  // boundaries.
  InputHandler::ScrollStatus status = host_impl_->ScrollBegin(
      BeginState(gfx::Point(15, 5)).get(), InputHandler::WHEEL);
  EXPECT_EQ(InputHandler::SCROLL_IGNORED, status.thread);
  EXPECT_EQ(MainThreadScrollingReason::kNoScrollingLayer,
            status.main_thread_scrolling_reasons);

  EXPECT_FALSE(did_request_redraw_);
  EXPECT_FALSE(did_request_commit_);
}

TEST_F(LayerTreeHostImplTest, ScrollMissesBackfacingChild) {
  gfx::Size surface_size(10, 10);
  scoped_ptr<LayerImpl> root = LayerImpl::Create(host_impl_->active_tree(), 1);
  root->SetForceRenderSurface(true);
  scoped_ptr<LayerImpl> child =
      CreateScrollableLayer(2, surface_size, root.get());
  host_impl_->SetViewportSize(surface_size);

  gfx::Transform matrix;
  matrix.RotateAboutXAxis(180.0);
  child->SetTransform(matrix);
  child->SetDoubleSided(false);

  root->AddChild(std::move(child));
  host_impl_->active_tree()->SetRootLayer(std::move(root));
  SetNeedsRebuildPropertyTrees();
  DrawFrame();

  // Scroll event is ignored because the scrollable layer is not facing the
  // viewer and there is nothing scrollable behind it.
  InputHandler::ScrollStatus status = host_impl_->ScrollBegin(
      BeginState(gfx::Point(5, 5)).get(), InputHandler::WHEEL);
  EXPECT_EQ(InputHandler::SCROLL_IGNORED, status.thread);
  EXPECT_EQ(MainThreadScrollingReason::kNoScrollingLayer,
            status.main_thread_scrolling_reasons);

  EXPECT_FALSE(did_request_redraw_);
  EXPECT_FALSE(did_request_commit_);
}

TEST_F(LayerTreeHostImplTest, ScrollBlockedByContentLayer) {
  gfx::Size surface_size(10, 10);
  scoped_ptr<LayerImpl> clip_layer =
      LayerImpl::Create(host_impl_->active_tree(), 3);
  scoped_ptr<LayerImpl> content_layer =
      CreateScrollableLayer(1, surface_size, clip_layer.get());
  content_layer->set_main_thread_scrolling_reasons(
      MainThreadScrollingReason::kHasBackgroundAttachmentFixedObjects);
  content_layer->SetScrollClipLayer(Layer::INVALID_ID);

  // Note: we can use the same clip layer for both since both calls to
  // CreateScrollableLayer() use the same surface size.
  scoped_ptr<LayerImpl> scroll_layer =
      CreateScrollableLayer(2, surface_size, clip_layer.get());
  scroll_layer->AddChild(std::move(content_layer));
  clip_layer->AddChild(std::move(scroll_layer));
  clip_layer->SetForceRenderSurface(true);

  host_impl_->active_tree()->SetRootLayer(std::move(clip_layer));
  host_impl_->SetViewportSize(surface_size);
  SetNeedsRebuildPropertyTrees();
  DrawFrame();

  // Scrolling fails because the content layer is asking to be scrolled on the
  // main thread.
  InputHandler::ScrollStatus status = host_impl_->ScrollBegin(
      BeginState(gfx::Point(5, 5)).get(), InputHandler::WHEEL);
  EXPECT_EQ(InputHandler::SCROLL_ON_MAIN_THREAD, status.thread);
  EXPECT_EQ(MainThreadScrollingReason::kHasBackgroundAttachmentFixedObjects,
            status.main_thread_scrolling_reasons);
}

TEST_F(LayerTreeHostImplTest, ScrollRootAndChangePageScaleOnMainThread) {
  gfx::Size viewport_size(20, 20);
  float page_scale = 2.f;

  SetupScrollAndContentsLayers(viewport_size);

  // Setup the layers so that the outer viewport is scrollable.
  host_impl_->active_tree()->InnerViewportScrollLayer()->parent()->SetBounds(
      viewport_size);
  host_impl_->active_tree()->OuterViewportScrollLayer()->SetBounds(
      gfx::Size(40, 40));
  host_impl_->active_tree()->PushPageScaleFromMainThread(1.f, 1.f, 2.f);
  DrawFrame();

  LayerImpl* root_scroll =
      host_impl_->active_tree()->OuterViewportScrollLayer();
  LayerImpl* inner_scroll =
      host_impl_->active_tree()->InnerViewportScrollLayer();
  EXPECT_EQ(viewport_size, root_scroll->scroll_clip_layer()->bounds());

  gfx::Vector2d scroll_delta(0, 10);
  gfx::Vector2d expected_scroll_delta = scroll_delta;
  gfx::ScrollOffset expected_max_scroll = root_scroll->MaxScrollOffset();
  EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
            host_impl_->ScrollBegin(BeginState(gfx::Point(5, 5)).get(),
                                    InputHandler::WHEEL)
                .thread);
  host_impl_->ScrollBy(UpdateState(gfx::Point(), scroll_delta).get());
  host_impl_->ScrollEnd(EndState().get());

  // Set new page scale from main thread.
  host_impl_->active_tree()->PushPageScaleFromMainThread(page_scale, 1.f, 2.f);

  scoped_ptr<ScrollAndScaleSet> scroll_info = host_impl_->ProcessScrollDeltas();
  EXPECT_TRUE(ScrollInfoContains(*scroll_info.get(), inner_scroll->id(),
                                 expected_scroll_delta));

  // The scroll range should also have been updated.
  EXPECT_EQ(expected_max_scroll, root_scroll->MaxScrollOffset());

  // The page scale delta remains constant because the impl thread did not
  // scale.
  EXPECT_EQ(1.f, host_impl_->active_tree()->page_scale_delta());
}

TEST_F(LayerTreeHostImplTest, ScrollRootAndChangePageScaleOnImplThread) {
  gfx::Size viewport_size(20, 20);
  float page_scale = 2.f;

  SetupScrollAndContentsLayers(viewport_size);

  // Setup the layers so that the outer viewport is scrollable.
  host_impl_->active_tree()->InnerViewportScrollLayer()->parent()->SetBounds(
      viewport_size);
  host_impl_->active_tree()->OuterViewportScrollLayer()->SetBounds(
      gfx::Size(40, 40));
  host_impl_->active_tree()->PushPageScaleFromMainThread(1.f, 1.f, 2.f);
  DrawFrame();

  LayerImpl* root_scroll =
      host_impl_->active_tree()->OuterViewportScrollLayer();
  LayerImpl* inner_scroll =
      host_impl_->active_tree()->InnerViewportScrollLayer();
  EXPECT_EQ(viewport_size, root_scroll->scroll_clip_layer()->bounds());

  gfx::Vector2d scroll_delta(0, 10);
  gfx::Vector2d expected_scroll_delta = scroll_delta;
  gfx::ScrollOffset expected_max_scroll = root_scroll->MaxScrollOffset();
  EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
            host_impl_->ScrollBegin(BeginState(gfx::Point(5, 5)).get(),
                                    InputHandler::WHEEL)
                .thread);
  host_impl_->ScrollBy(UpdateState(gfx::Point(), scroll_delta).get());
  host_impl_->ScrollEnd(EndState().get());

  // Set new page scale on impl thread by pinching.
  host_impl_->ScrollBegin(BeginState(gfx::Point()).get(),
                          InputHandler::TOUCHSCREEN);
  host_impl_->PinchGestureBegin();
  host_impl_->PinchGestureUpdate(page_scale, gfx::Point());
  host_impl_->PinchGestureEnd();
  host_impl_->ScrollEnd(EndState().get());
  DrawOneFrame();

  // The scroll delta is not scaled because the main thread did not scale.
  scoped_ptr<ScrollAndScaleSet> scroll_info = host_impl_->ProcessScrollDeltas();
  EXPECT_TRUE(ScrollInfoContains(*scroll_info.get(), inner_scroll->id(),
                                 expected_scroll_delta));

  // The scroll range should also have been updated.
  EXPECT_EQ(expected_max_scroll, root_scroll->MaxScrollOffset());

  // The page scale delta should match the new scale on the impl side.
  EXPECT_EQ(page_scale, host_impl_->active_tree()->current_page_scale_factor());
}

TEST_F(LayerTreeHostImplTest, PageScaleDeltaAppliedToRootScrollLayerOnly) {
  host_impl_->active_tree()->PushPageScaleFromMainThread(1.f, 1.f, 2.f);
  gfx::Size surface_size(10, 10);
  float default_page_scale = 1.f;
  gfx::Transform default_page_scale_matrix;
  default_page_scale_matrix.Scale(default_page_scale, default_page_scale);

  float new_page_scale = 2.f;
  gfx::Transform new_page_scale_matrix;
  new_page_scale_matrix.Scale(new_page_scale, new_page_scale);

  // Create a normal scrollable root layer and another scrollable child layer.
  LayerImpl* scroll = SetupScrollAndContentsLayers(surface_size);
  scroll->SetDrawsContent(true);
  LayerImpl* root = host_impl_->active_tree()->root_layer();
  LayerImpl* child = scroll->children()[0].get();
  child->SetDrawsContent(true);

  scoped_ptr<LayerImpl> scrollable_child_clip =
      LayerImpl::Create(host_impl_->active_tree(), 6);
  scoped_ptr<LayerImpl> scrollable_child =
      CreateScrollableLayer(7, surface_size, scrollable_child_clip.get());
  scrollable_child_clip->AddChild(std::move(scrollable_child));
  child->AddChild(std::move(scrollable_child_clip));
  LayerImpl* grand_child = child->children()[0].get();
  grand_child->SetDrawsContent(true);

  // Set new page scale on impl thread by pinching.
  SetNeedsRebuildPropertyTrees();
  RebuildPropertyTrees();
  host_impl_->ScrollBegin(BeginState(gfx::Point()).get(),
                          InputHandler::TOUCHSCREEN);
  host_impl_->PinchGestureBegin();
  host_impl_->PinchGestureUpdate(new_page_scale, gfx::Point());
  host_impl_->PinchGestureEnd();
  host_impl_->ScrollEnd(EndState().get());
  DrawOneFrame();

  // Make sure all the layers are drawn with the page scale delta applied, i.e.,
  // the page scale delta on the root layer is applied hierarchically.
  LayerTreeHostImpl::FrameData frame;
  EXPECT_EQ(DRAW_SUCCESS, PrepareToDrawFrame(&frame));
  host_impl_->DrawLayers(&frame);
  host_impl_->DidDrawAllLayers(frame);

  EXPECT_EQ(1.f, root->DrawTransform().matrix().getDouble(0, 0));
  EXPECT_EQ(1.f, root->DrawTransform().matrix().getDouble(1, 1));
  EXPECT_EQ(new_page_scale, scroll->DrawTransform().matrix().getDouble(0, 0));
  EXPECT_EQ(new_page_scale, scroll->DrawTransform().matrix().getDouble(1, 1));
  EXPECT_EQ(new_page_scale, child->DrawTransform().matrix().getDouble(0, 0));
  EXPECT_EQ(new_page_scale, child->DrawTransform().matrix().getDouble(1, 1));
  EXPECT_EQ(new_page_scale,
            grand_child->DrawTransform().matrix().getDouble(0, 0));
  EXPECT_EQ(new_page_scale,
            grand_child->DrawTransform().matrix().getDouble(1, 1));
}

TEST_F(LayerTreeHostImplTest, ScrollChildAndChangePageScaleOnMainThread) {
  SetupScrollAndContentsLayers(gfx::Size(30, 30));

  LayerImpl* outer_scroll = host_impl_->OuterViewportScrollLayer();
  LayerImpl* inner_scroll = host_impl_->InnerViewportScrollLayer();

  // Make the outer scroll layer scrollable.
  outer_scroll->SetBounds(gfx::Size(50, 50));

  DrawFrame();

  gfx::Vector2d scroll_delta(0, 10);
  gfx::Vector2d expected_scroll_delta(scroll_delta);
  gfx::ScrollOffset expected_max_scroll(outer_scroll->MaxScrollOffset());
  EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
            host_impl_->ScrollBegin(BeginState(gfx::Point(5, 5)).get(),
                                    InputHandler::WHEEL)
                .thread);
  host_impl_->ScrollBy(UpdateState(gfx::Point(), scroll_delta).get());
  host_impl_->ScrollEnd(EndState().get());

  float page_scale = 2.f;
  host_impl_->active_tree()->PushPageScaleFromMainThread(page_scale, 1.f,
                                                         page_scale);

  DrawOneFrame();

  scoped_ptr<ScrollAndScaleSet> scroll_info = host_impl_->ProcessScrollDeltas();
  EXPECT_TRUE(ScrollInfoContains(*scroll_info.get(), inner_scroll->id(),
                                 expected_scroll_delta));

  // The scroll range should not have changed.
  EXPECT_EQ(outer_scroll->MaxScrollOffset(), expected_max_scroll);

  // The page scale delta remains constant because the impl thread did not
  // scale.
  EXPECT_EQ(1.f, host_impl_->active_tree()->page_scale_delta());
}

TEST_F(LayerTreeHostImplTest, ScrollChildBeyondLimit) {
  // Scroll a child layer beyond its maximum scroll range and make sure the
  // parent layer isn't scrolled.
  gfx::Size surface_size(10, 10);
  gfx::Size content_size(20, 20);
  scoped_ptr<LayerImpl> root = LayerImpl::Create(host_impl_->active_tree(), 1);
  root->SetBounds(surface_size);
  root->SetForceRenderSurface(true);
  scoped_ptr<LayerImpl> grand_child =
      CreateScrollableLayer(3, content_size, root.get());

  scoped_ptr<LayerImpl> child =
      CreateScrollableLayer(2, content_size, root.get());
  LayerImpl* grand_child_layer = grand_child.get();
  child->AddChild(std::move(grand_child));

  LayerImpl* child_layer = child.get();
  root->AddChild(std::move(child));
  host_impl_->active_tree()->SetRootLayer(std::move(root));
  host_impl_->active_tree()->DidBecomeActive();
  host_impl_->SetViewportSize(surface_size);
  grand_child_layer->layer_tree_impl()
      ->property_trees()
      ->scroll_tree.UpdateScrollOffsetBaseForTesting(grand_child_layer->id(),
                                                     gfx::ScrollOffset(0, 5));
  child_layer->layer_tree_impl()
      ->property_trees()
      ->scroll_tree.UpdateScrollOffsetBaseForTesting(child_layer->id(),
                                                     gfx::ScrollOffset(3, 0));

  SetNeedsRebuildPropertyTrees();
  DrawFrame();
  {
    gfx::Vector2d scroll_delta(-8, -7);
    EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
              host_impl_->ScrollBegin(BeginState(gfx::Point()).get(),
                                      InputHandler::WHEEL)
                  .thread);
    host_impl_->ScrollBy(UpdateState(gfx::Point(), scroll_delta).get());
    host_impl_->ScrollEnd(EndState().get());

    scoped_ptr<ScrollAndScaleSet> scroll_info =
        host_impl_->ProcessScrollDeltas();

    // The grand child should have scrolled up to its limit.
    LayerImpl* child =
        host_impl_->active_tree()->root_layer()->children()[0].get();
    LayerImpl* grand_child = child->children()[0].get();
    EXPECT_TRUE(ScrollInfoContains(*scroll_info.get(), grand_child->id(),
                                   gfx::Vector2d(0, -5)));

    // The child should not have scrolled.
    ExpectNone(*scroll_info.get(), child->id());
  }
}

TEST_F(LayerTreeHostImplTest, ScrollWithoutBubbling) {
  // Scroll a child layer beyond its maximum scroll range and make sure the
  // the scroll doesn't bubble up to the parent layer.
  gfx::Size surface_size(20, 20);
  gfx::Size viewport_size(10, 10);
  scoped_ptr<LayerImpl> root_ptr =
      LayerImpl::Create(host_impl_->active_tree(), 1);
  scoped_ptr<LayerImpl> root_clip =
      LayerImpl::Create(host_impl_->active_tree(), 2);
  root_clip->SetForceRenderSurface(true);
  scoped_ptr<LayerImpl> root_scrolling =
      CreateScrollableLayer(3, surface_size, root_clip.get());
  root_scrolling->SetIsContainerForFixedPositionLayers(true);

  scoped_ptr<LayerImpl> grand_child =
      CreateScrollableLayer(5, surface_size, root_clip.get());

  scoped_ptr<LayerImpl> child =
      CreateScrollableLayer(4, surface_size, root_clip.get());
  LayerImpl* grand_child_layer = grand_child.get();
  child->AddChild(std::move(grand_child));

  LayerImpl* child_layer = child.get();
  root_scrolling->AddChild(std::move(child));
  root_clip->AddChild(std::move(root_scrolling));
  EXPECT_EQ(viewport_size, root_clip->bounds());
  root_ptr->AddChild(std::move(root_clip));
  host_impl_->active_tree()->SetRootLayer(std::move(root_ptr));
  host_impl_->active_tree()->SetViewportLayersFromIds(Layer::INVALID_ID, 1, 3,
                                                      Layer::INVALID_ID);
  host_impl_->active_tree()->DidBecomeActive();
  host_impl_->SetViewportSize(viewport_size);

  grand_child_layer->layer_tree_impl()
      ->property_trees()
      ->scroll_tree.UpdateScrollOffsetBaseForTesting(grand_child_layer->id(),
                                                     gfx::ScrollOffset(0, 2));
  child_layer->layer_tree_impl()
      ->property_trees()
      ->scroll_tree.UpdateScrollOffsetBaseForTesting(child_layer->id(),
                                                     gfx::ScrollOffset(0, 3));

  SetNeedsRebuildPropertyTrees();
  DrawFrame();
  {
    gfx::Vector2d scroll_delta(0, -10);
    EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
              host_impl_->ScrollBegin(BeginState(gfx::Point()).get(),
                                      InputHandler::NON_BUBBLING_GESTURE)
                  .thread);
    host_impl_->ScrollBy(UpdateState(gfx::Point(), scroll_delta).get());
    host_impl_->ScrollEnd(EndState().get());

    scoped_ptr<ScrollAndScaleSet> scroll_info =
        host_impl_->ProcessScrollDeltas();

    // The grand child should have scrolled up to its limit.
    LayerImpl* child = host_impl_->active_tree()
                           ->root_layer()
                           ->children()[0]
                           ->children()[0]
                           ->children()[0]
                           .get();
    LayerImpl* grand_child = child->children()[0].get();
    EXPECT_TRUE(ScrollInfoContains(*scroll_info.get(), grand_child->id(),
                                   gfx::Vector2d(0, -2)));

    // The child should not have scrolled.
    ExpectNone(*scroll_info.get(), child->id());

    // The next time we scroll we should only scroll the parent.
    scroll_delta = gfx::Vector2d(0, -3);
    EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
              host_impl_->ScrollBegin(BeginState(gfx::Point(5, 5)).get(),
                                      InputHandler::NON_BUBBLING_GESTURE)
                  .thread);
    EXPECT_EQ(host_impl_->CurrentlyScrollingLayer(), grand_child);
    host_impl_->ScrollBy(UpdateState(gfx::Point(), scroll_delta).get());
    EXPECT_EQ(host_impl_->CurrentlyScrollingLayer(), child);
    host_impl_->ScrollEnd(EndState().get());

    scroll_info = host_impl_->ProcessScrollDeltas();

    // The child should have scrolled up to its limit.
    EXPECT_TRUE(ScrollInfoContains(*scroll_info.get(), child->id(),
                                   gfx::Vector2d(0, -3)));

    // The grand child should not have scrolled.
    EXPECT_TRUE(ScrollInfoContains(*scroll_info.get(), grand_child->id(),
                                   gfx::Vector2d(0, -2)));

    // After scrolling the parent, another scroll on the opposite direction
    // should still scroll the child.
    scroll_delta = gfx::Vector2d(0, 7);
    EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
              host_impl_->ScrollBegin(BeginState(gfx::Point(5, 5)).get(),
                                      InputHandler::NON_BUBBLING_GESTURE)
                  .thread);
    EXPECT_EQ(host_impl_->CurrentlyScrollingLayer(), grand_child);
    host_impl_->ScrollBy(UpdateState(gfx::Point(), scroll_delta).get());
    EXPECT_EQ(host_impl_->CurrentlyScrollingLayer(), grand_child);
    host_impl_->ScrollEnd(EndState().get());

    scroll_info = host_impl_->ProcessScrollDeltas();

    // The grand child should have scrolled.
    EXPECT_TRUE(ScrollInfoContains(*scroll_info.get(), grand_child->id(),
                                   gfx::Vector2d(0, 5)));

    // The child should not have scrolled.
    EXPECT_TRUE(ScrollInfoContains(*scroll_info.get(), child->id(),
                                   gfx::Vector2d(0, -3)));

    // Scrolling should be adjusted from viewport space.
    host_impl_->active_tree()->PushPageScaleFromMainThread(2.f, 2.f, 2.f);
    host_impl_->active_tree()->SetPageScaleOnActiveTree(2.f);

    scroll_delta = gfx::Vector2d(0, -2);
    EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
              host_impl_->ScrollBegin(BeginState(gfx::Point(1, 1)).get(),
                                      InputHandler::NON_BUBBLING_GESTURE)
                  .thread);
    EXPECT_EQ(grand_child, host_impl_->CurrentlyScrollingLayer());
    host_impl_->ScrollBy(UpdateState(gfx::Point(), scroll_delta).get());
    host_impl_->ScrollEnd(EndState().get());

    scroll_info = host_impl_->ProcessScrollDeltas();

    // Should have scrolled by half the amount in layer space (5 - 2/2)
    EXPECT_TRUE(ScrollInfoContains(*scroll_info.get(), grand_child->id(),
                                   gfx::Vector2d(0, 4)));
  }
}
TEST_F(LayerTreeHostImplTest, ScrollEventBubbling) {
  // When we try to scroll a non-scrollable child layer, the scroll delta
  // should be applied to one of its ancestors if possible.
  gfx::Size surface_size(10, 10);
  gfx::Size content_size(20, 20);
  scoped_ptr<LayerImpl> root_ptr =
      LayerImpl::Create(host_impl_->active_tree(), 4);
  scoped_ptr<LayerImpl> root_clip =
      LayerImpl::Create(host_impl_->active_tree(), 3);
  root_clip->SetForceRenderSurface(true);
  scoped_ptr<LayerImpl> root_scroll =
      CreateScrollableLayer(1, content_size, root_clip.get());
  // Make 'root' the clip layer for child: since they have the same sizes the
  // child will have zero max_scroll_offset and scrolls will bubble.
  scoped_ptr<LayerImpl> child =
      CreateScrollableLayer(2, content_size, root_scroll.get());
  child->SetIsContainerForFixedPositionLayers(true);
  root_scroll->SetBounds(content_size);

  int root_scroll_id = root_scroll->id();
  root_scroll->AddChild(std::move(child));
  root_clip->AddChild(std::move(root_scroll));
  root_ptr->AddChild(std::move(root_clip));

  host_impl_->SetViewportSize(surface_size);
  host_impl_->active_tree()->SetRootLayer(std::move(root_ptr));
  host_impl_->active_tree()->SetViewportLayersFromIds(Layer::INVALID_ID, 4, 2,
                                                      Layer::INVALID_ID);
  host_impl_->active_tree()->DidBecomeActive();
  SetNeedsRebuildPropertyTrees();
  DrawFrame();
  {
    gfx::Vector2d scroll_delta(0, 4);
    EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
              host_impl_->ScrollBegin(BeginState(gfx::Point(5, 5)).get(),
                                      InputHandler::WHEEL)
                  .thread);
    host_impl_->ScrollBy(UpdateState(gfx::Point(), scroll_delta).get());
    host_impl_->ScrollEnd(EndState().get());

    scoped_ptr<ScrollAndScaleSet> scroll_info =
        host_impl_->ProcessScrollDeltas();

    // Only the root scroll should have scrolled.
    ASSERT_EQ(scroll_info->scrolls.size(), 1u);
    EXPECT_TRUE(
        ScrollInfoContains(*scroll_info.get(), root_scroll_id, scroll_delta));
  }
}

TEST_F(LayerTreeHostImplTest, ScrollBeforeRedraw) {
  gfx::Size surface_size(10, 10);
  scoped_ptr<LayerImpl> root_ptr =
      LayerImpl::Create(host_impl_->active_tree(), 1);
  scoped_ptr<LayerImpl> root_clip =
      LayerImpl::Create(host_impl_->active_tree(), 2);
  scoped_ptr<LayerImpl> root_scroll =
      CreateScrollableLayer(3, surface_size, root_clip.get());
  root_scroll->SetIsContainerForFixedPositionLayers(true);
  root_clip->SetForceRenderSurface(true);
  root_clip->AddChild(std::move(root_scroll));
  root_ptr->AddChild(std::move(root_clip));
  host_impl_->active_tree()->SetRootLayer(std::move(root_ptr));
  host_impl_->active_tree()->SetViewportLayersFromIds(Layer::INVALID_ID, 1, 3,
                                                      Layer::INVALID_ID);
  host_impl_->active_tree()->DidBecomeActive();
  host_impl_->SetViewportSize(surface_size);

  // Draw one frame and then immediately rebuild the layer tree to mimic a tree
  // synchronization.
  SetNeedsRebuildPropertyTrees();
  DrawFrame();
  host_impl_->active_tree()->DetachLayerTree();
  scoped_ptr<LayerImpl> root_ptr2 =
      LayerImpl::Create(host_impl_->active_tree(), 4);
  scoped_ptr<LayerImpl> root_clip2 =
      LayerImpl::Create(host_impl_->active_tree(), 5);
  scoped_ptr<LayerImpl> root_scroll2 =
      CreateScrollableLayer(6, surface_size, root_clip2.get());
  root_scroll2->SetIsContainerForFixedPositionLayers(true);
  root_clip2->AddChild(std::move(root_scroll2));
  root_clip2->SetForceRenderSurface(true);
  root_ptr2->AddChild(std::move(root_clip2));
  host_impl_->active_tree()->SetRootLayer(std::move(root_ptr2));
  host_impl_->active_tree()->SetViewportLayersFromIds(Layer::INVALID_ID, 4, 6,
                                                      Layer::INVALID_ID);
  host_impl_->active_tree()->DidBecomeActive();

  // Scrolling should still work even though we did not draw yet.
  SetNeedsRebuildPropertyTrees();
  RebuildPropertyTrees();
  EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
            host_impl_->ScrollBegin(BeginState(gfx::Point(5, 5)).get(),
                                    InputHandler::WHEEL)
                .thread);
}

TEST_F(LayerTreeHostImplTest, ScrollAxisAlignedRotatedLayer) {
  LayerImpl* scroll_layer = SetupScrollAndContentsLayers(gfx::Size(100, 100));
  scroll_layer->SetDrawsContent(true);

  // Rotate the root layer 90 degrees counter-clockwise about its center.
  gfx::Transform rotate_transform;
  rotate_transform.Rotate(-90.0);
  host_impl_->active_tree()->root_layer()->SetTransform(rotate_transform);

  gfx::Size surface_size(50, 50);
  host_impl_->SetViewportSize(surface_size);
  SetNeedsRebuildPropertyTrees();
  DrawFrame();

  // Scroll to the right in screen coordinates with a gesture.
  gfx::Vector2d gesture_scroll_delta(10, 0);
  EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
            host_impl_
                ->ScrollBegin(BeginState(gfx::Point()).get(),
                              InputHandler::TOUCHSCREEN)
                .thread);
  host_impl_->ScrollBy(UpdateState(gfx::Point(), gesture_scroll_delta).get());
  host_impl_->ScrollEnd(EndState().get());

  // The layer should have scrolled down in its local coordinates.
  scoped_ptr<ScrollAndScaleSet> scroll_info = host_impl_->ProcessScrollDeltas();
  EXPECT_TRUE(ScrollInfoContains(*scroll_info.get(), scroll_layer->id(),
                                 gfx::Vector2d(0, gesture_scroll_delta.x())));

  // Reset and scroll down with the wheel.
  SetScrollOffsetDelta(scroll_layer, gfx::Vector2dF());
  gfx::Vector2d wheel_scroll_delta(0, 10);
  EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
            host_impl_->ScrollBegin(BeginState(gfx::Point()).get(),
                                    InputHandler::WHEEL)
                .thread);
  host_impl_->ScrollBy(UpdateState(gfx::Point(), wheel_scroll_delta).get());
  host_impl_->ScrollEnd(EndState().get());

  // The layer should have scrolled down in its local coordinates.
  scroll_info = host_impl_->ProcessScrollDeltas();
  EXPECT_TRUE(ScrollInfoContains(*scroll_info.get(), scroll_layer->id(),
                                 wheel_scroll_delta));
}

TEST_F(LayerTreeHostImplTest, ScrollNonAxisAlignedRotatedLayer) {
  LayerImpl* scroll_layer = SetupScrollAndContentsLayers(gfx::Size(100, 100));
  int child_clip_layer_id = 6;
  int child_layer_id = 7;
  float child_layer_angle = -20.f;

  // Create a child layer that is rotated to a non-axis-aligned angle.
  scoped_ptr<LayerImpl> clip_layer =
      LayerImpl::Create(host_impl_->active_tree(), child_clip_layer_id);
  scoped_ptr<LayerImpl> child = CreateScrollableLayer(
      child_layer_id, scroll_layer->bounds(), clip_layer.get());
  gfx::Transform rotate_transform;
  rotate_transform.Translate(-50.0, -50.0);
  rotate_transform.Rotate(child_layer_angle);
  rotate_transform.Translate(50.0, 50.0);
  clip_layer->SetTransform(rotate_transform);

  // Only allow vertical scrolling.
  clip_layer->SetBounds(
      gfx::Size(child->bounds().width(), child->bounds().height() / 2));
  // The rotation depends on the layer's transform origin, and the child layer
  // is a different size than the clip, so make sure the clip layer's origin
  // lines up over the child.
  clip_layer->SetTransformOrigin(gfx::Point3F(
      clip_layer->bounds().width() * 0.5f, clip_layer->bounds().height(), 0.f));
  LayerImpl* child_ptr = child.get();
  clip_layer->AddChild(std::move(child));
  scroll_layer->AddChild(std::move(clip_layer));

  gfx::Size surface_size(50, 50);
  host_impl_->SetViewportSize(surface_size);
  SetNeedsRebuildPropertyTrees();
  DrawFrame();
  {
    // Scroll down in screen coordinates with a gesture.
    gfx::Vector2d gesture_scroll_delta(0, 10);
    EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
              host_impl_
                  ->ScrollBegin(BeginState(gfx::Point(1, 1)).get(),
                                InputHandler::TOUCHSCREEN)
                  .thread);
    host_impl_->ScrollBy(UpdateState(gfx::Point(), gesture_scroll_delta).get());
    host_impl_->ScrollEnd(EndState().get());

    // The child layer should have scrolled down in its local coordinates an
    // amount proportional to the angle between it and the input scroll delta.
    gfx::Vector2d expected_scroll_delta(
        0, gesture_scroll_delta.y() *
               std::cos(MathUtil::Deg2Rad(child_layer_angle)));
    scoped_ptr<ScrollAndScaleSet> scroll_info =
        host_impl_->ProcessScrollDeltas();
    EXPECT_TRUE(ScrollInfoContains(*scroll_info.get(), child_layer_id,
                                   expected_scroll_delta));

    // The root scroll layer should not have scrolled, because the input delta
    // was close to the layer's axis of movement.
    EXPECT_EQ(scroll_info->scrolls.size(), 1u);
  }
  {
    // Now reset and scroll the same amount horizontally.
    SetScrollOffsetDelta(child_ptr, gfx::Vector2dF());
    gfx::Vector2d gesture_scroll_delta(10, 0);
    EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
              host_impl_
                  ->ScrollBegin(BeginState(gfx::Point(1, 1)).get(),
                                InputHandler::TOUCHSCREEN)
                  .thread);
    host_impl_->ScrollBy(UpdateState(gfx::Point(), gesture_scroll_delta).get());
    host_impl_->ScrollEnd(EndState().get());

    // The child layer shouldn't have scrolled.
    gfx::Vector2d expected_scroll_delta(
        0, -gesture_scroll_delta.x() *
               std::sin(MathUtil::Deg2Rad(child_layer_angle)));
    scoped_ptr<ScrollAndScaleSet> scroll_info =
        host_impl_->ProcessScrollDeltas();
    EXPECT_TRUE(ScrollInfoContains(*scroll_info.get(), child_layer_id,
                                   expected_scroll_delta));

    // The root scroll layer shouldn't have scrolled.
    ExpectNone(*scroll_info.get(), scroll_layer->id());
  }
}

TEST_F(LayerTreeHostImplTest, ScrollPerspectiveTransformedLayer) {
  // When scrolling an element with perspective, the distance scrolled
  // depends on the point at which the scroll begins.
  LayerImpl* scroll_layer = SetupScrollAndContentsLayers(gfx::Size(100, 100));
  int child_clip_layer_id = 6;
  int child_layer_id = 7;

  // Create a child layer that is rotated on its x axis, with perspective.
  scoped_ptr<LayerImpl> clip_layer =
      LayerImpl::Create(host_impl_->active_tree(), child_clip_layer_id);
  scoped_ptr<LayerImpl> child = CreateScrollableLayer(
      child_layer_id, scroll_layer->bounds(), clip_layer.get());
  LayerImpl* child_ptr = child.get();
  gfx::Transform perspective_transform;
  perspective_transform.Translate(-50.0, -50.0);
  perspective_transform.ApplyPerspectiveDepth(20);
  perspective_transform.RotateAboutXAxis(45);
  perspective_transform.Translate(50.0, 50.0);
  clip_layer->SetTransform(perspective_transform);

  clip_layer->SetBounds(gfx::Size(child_ptr->bounds().width() / 2,
                                  child_ptr->bounds().height() / 2));
  // The transform depends on the layer's transform origin, and the child layer
  // is a different size than the clip, so make sure the clip layer's origin
  // lines up over the child.
  clip_layer->SetTransformOrigin(gfx::Point3F(
      clip_layer->bounds().width(), clip_layer->bounds().height(), 0.f));
  clip_layer->AddChild(std::move(child));
  scroll_layer->AddChild(std::move(clip_layer));

  gfx::Size surface_size(50, 50);
  host_impl_->SetViewportSize(surface_size);

  scoped_ptr<ScrollAndScaleSet> scroll_info;

  gfx::Vector2d gesture_scroll_deltas[4];
  gesture_scroll_deltas[0] = gfx::Vector2d(4, 10);
  gesture_scroll_deltas[1] = gfx::Vector2d(4, 10);
  gesture_scroll_deltas[2] = gfx::Vector2d(10, 0);
  gesture_scroll_deltas[3] = gfx::Vector2d(10, 0);

  gfx::Vector2d expected_scroll_deltas[4];
  // Perspective affects the vertical delta by a different
  // amount depending on the vertical position of the |viewport_point|.
  expected_scroll_deltas[0] = gfx::Vector2d(2, 8);
  expected_scroll_deltas[1] = gfx::Vector2d(1, 4);
  // Deltas which start with the same vertical position of the
  // |viewport_point| are subject to identical perspective effects.
  expected_scroll_deltas[2] = gfx::Vector2d(4, 0);
  expected_scroll_deltas[3] = gfx::Vector2d(4, 0);

  gfx::Point viewport_point(1, 1);

  SetNeedsRebuildPropertyTrees();
  // Scroll in screen coordinates with a gesture. Each scroll starts
  // where the previous scroll ended, but the scroll position is reset
  // for each scroll.
  for (int i = 0; i < 4; ++i) {
    SetScrollOffsetDelta(child_ptr, gfx::Vector2dF());
    DrawFrame();
    EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
              host_impl_
                  ->ScrollBegin(BeginState(viewport_point).get(),
                                InputHandler::TOUCHSCREEN)
                  .thread);
    host_impl_->ScrollBy(
        UpdateState(viewport_point, gesture_scroll_deltas[i]).get());
    viewport_point += gesture_scroll_deltas[i];
    host_impl_->ScrollEnd(EndState().get());

    scroll_info = host_impl_->ProcessScrollDeltas();
    EXPECT_TRUE(ScrollInfoContains(*scroll_info.get(), child_layer_id,
                                   expected_scroll_deltas[i]));

    // The root scroll layer should not have scrolled, because the input delta
    // was close to the layer's axis of movement.
    EXPECT_EQ(scroll_info->scrolls.size(), 1u);
  }
}

TEST_F(LayerTreeHostImplTest, ScrollScaledLayer) {
  LayerImpl* scroll_layer =
      SetupScrollAndContentsLayers(gfx::Size(100, 100));

  // Scale the layer to twice its normal size.
  int scale = 2;
  gfx::Transform scale_transform;
  scale_transform.Scale(scale, scale);
  scroll_layer->parent()->SetTransform(scale_transform);

  gfx::Size surface_size(50, 50);
  host_impl_->SetViewportSize(surface_size);
  SetNeedsRebuildPropertyTrees();
  DrawFrame();

  // Scroll down in screen coordinates with a gesture.
  gfx::Vector2d scroll_delta(0, 10);
  EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
            host_impl_
                ->ScrollBegin(BeginState(gfx::Point()).get(),
                              InputHandler::TOUCHSCREEN)
                .thread);
  host_impl_->ScrollBy(UpdateState(gfx::Point(), scroll_delta).get());
  host_impl_->ScrollEnd(EndState().get());

  // The layer should have scrolled down in its local coordinates, but half the
  // amount.
  scoped_ptr<ScrollAndScaleSet> scroll_info = host_impl_->ProcessScrollDeltas();
  EXPECT_TRUE(ScrollInfoContains(*scroll_info.get(), scroll_layer->id(),
                                 gfx::Vector2d(0, scroll_delta.y() / scale)));

  // Reset and scroll down with the wheel.
  SetScrollOffsetDelta(scroll_layer, gfx::Vector2dF());
  gfx::Vector2d wheel_scroll_delta(0, 10);
  EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
            host_impl_->ScrollBegin(BeginState(gfx::Point()).get(),
                                    InputHandler::WHEEL)
                .thread);
  host_impl_->ScrollBy(UpdateState(gfx::Point(), wheel_scroll_delta).get());
  host_impl_->ScrollEnd(EndState().get());

  // It should apply the scale factor to the scroll delta for the wheel event.
  scroll_info = host_impl_->ProcessScrollDeltas();
  EXPECT_TRUE(ScrollInfoContains(*scroll_info.get(), scroll_layer->id(),
                                 wheel_scroll_delta));
}

TEST_F(LayerTreeHostImplTest, ScrollViewportRounding) {
  int width = 332;
  int height = 20;
  int scale = 3;
  SetupScrollAndContentsLayers(gfx::Size(width, height));
  host_impl_->active_tree()->InnerViewportContainerLayer()->SetBounds(
      gfx::Size(width * scale - 1, height * scale));
  SetNeedsRebuildPropertyTrees();
  RebuildPropertyTrees();
  host_impl_->active_tree()->SetDeviceScaleFactor(scale);
  host_impl_->active_tree()->PushPageScaleFromMainThread(1.f, 0.5f, 4.f);

  LayerImpl* inner_viewport_scroll_layer =
      host_impl_->active_tree()->InnerViewportScrollLayer();
  EXPECT_EQ(gfx::ScrollOffset(0, 0),
            inner_viewport_scroll_layer->MaxScrollOffset());
}

class TestInputHandlerClient : public InputHandlerClient {
 public:
  TestInputHandlerClient()
      : page_scale_factor_(0.f),
        min_page_scale_factor_(-1.f),
        max_page_scale_factor_(-1.f) {}
  ~TestInputHandlerClient() override {}

  // InputHandlerClient implementation.
  void WillShutdown() override {}
  void Animate(base::TimeTicks time) override {}
  void MainThreadHasStoppedFlinging() override {}
  void ReconcileElasticOverscrollAndRootScroll() override {}
  void UpdateRootLayerStateForSynchronousInputHandler(
      const gfx::ScrollOffset& total_scroll_offset,
      const gfx::ScrollOffset& max_scroll_offset,
      const gfx::SizeF& scrollable_size,
      float page_scale_factor,
      float min_page_scale_factor,
      float max_page_scale_factor) override {
    DCHECK(total_scroll_offset.x() <= max_scroll_offset.x());
    DCHECK(total_scroll_offset.y() <= max_scroll_offset.y());
    last_set_scroll_offset_ = total_scroll_offset;
    max_scroll_offset_ = max_scroll_offset;
    scrollable_size_ = scrollable_size;
    page_scale_factor_ = page_scale_factor;
    min_page_scale_factor_ = min_page_scale_factor;
    max_page_scale_factor_ = max_page_scale_factor;
  }

  gfx::ScrollOffset last_set_scroll_offset() {
    return last_set_scroll_offset_;
  }

  gfx::ScrollOffset max_scroll_offset() const {
    return max_scroll_offset_;
  }

  gfx::SizeF scrollable_size() const {
    return scrollable_size_;
  }

  float page_scale_factor() const {
    return page_scale_factor_;
  }

  float min_page_scale_factor() const {
    return min_page_scale_factor_;
  }

  float max_page_scale_factor() const {
    return max_page_scale_factor_;
  }

 private:
  gfx::ScrollOffset last_set_scroll_offset_;
  gfx::ScrollOffset max_scroll_offset_;
  gfx::SizeF scrollable_size_;
  float page_scale_factor_;
  float min_page_scale_factor_;
  float max_page_scale_factor_;
};

TEST_F(LayerTreeHostImplTest, RootLayerScrollOffsetDelegation) {
  TestInputHandlerClient scroll_watcher;
  host_impl_->SetViewportSize(gfx::Size(10, 20));
  LayerImpl* scroll_layer = SetupScrollAndContentsLayers(gfx::Size(100, 100));
  LayerImpl* clip_layer = scroll_layer->parent()->parent();
  SetNeedsRebuildPropertyTrees();
  clip_layer->SetBounds(gfx::Size(10, 20));
  RebuildPropertyTrees();

  host_impl_->BindToClient(&scroll_watcher);

  gfx::Vector2dF initial_scroll_delta(10.f, 10.f);
  scroll_layer->layer_tree_impl()
      ->property_trees()
      ->scroll_tree.UpdateScrollOffsetBaseForTesting(scroll_layer->id(),
                                                     gfx::ScrollOffset());
  SetScrollOffsetDelta(scroll_layer, initial_scroll_delta);

  EXPECT_EQ(gfx::ScrollOffset(), scroll_watcher.last_set_scroll_offset());

  // Requesting an update results in the current scroll offset being set.
  host_impl_->RequestUpdateForSynchronousInputHandler();
  EXPECT_EQ(gfx::ScrollOffset(initial_scroll_delta),
            scroll_watcher.last_set_scroll_offset());

  // Setting the delegate results in the scrollable_size, max_scroll_offset,
  // page_scale_factor and {min|max}_page_scale_factor being set.
  EXPECT_EQ(gfx::SizeF(100, 100), scroll_watcher.scrollable_size());
  EXPECT_EQ(gfx::ScrollOffset(90, 80), scroll_watcher.max_scroll_offset());
  EXPECT_EQ(1.f, scroll_watcher.page_scale_factor());
  EXPECT_EQ(1.f, scroll_watcher.min_page_scale_factor());
  EXPECT_EQ(1.f, scroll_watcher.max_page_scale_factor());

  // Put a page scale on the tree.
  host_impl_->active_tree()->PushPageScaleFromMainThread(2.f, 0.5f, 4.f);
  EXPECT_EQ(1.f, scroll_watcher.page_scale_factor());
  EXPECT_EQ(1.f, scroll_watcher.min_page_scale_factor());
  EXPECT_EQ(1.f, scroll_watcher.max_page_scale_factor());
  // Activation will update the delegate.
  host_impl_->ActivateSyncTree();
  EXPECT_EQ(2.f, scroll_watcher.page_scale_factor());
  EXPECT_EQ(.5f, scroll_watcher.min_page_scale_factor());
  EXPECT_EQ(4.f, scroll_watcher.max_page_scale_factor());

  // Animating page scale can change the root offset, so it should update the
  // delegate. Also resets the page scale to 1 for the rest of the test.
  host_impl_->LayerTreeHostImpl::StartPageScaleAnimation(
      gfx::Vector2d(0, 0), false, 1.f, base::TimeDelta());
  host_impl_->Animate();
  EXPECT_EQ(1.f, scroll_watcher.page_scale_factor());
  EXPECT_EQ(.5f, scroll_watcher.min_page_scale_factor());
  EXPECT_EQ(4.f, scroll_watcher.max_page_scale_factor());

  // The pinch gesture doesn't put the delegate into a state where the scroll
  // offset is outside of the scroll range.  (this is verified by DCHECKs in the
  // delegate).
  host_impl_->ScrollBegin(BeginState(gfx::Point()).get(),
                          InputHandler::TOUCHSCREEN);
  host_impl_->PinchGestureBegin();
  host_impl_->PinchGestureUpdate(2.f, gfx::Point());
  host_impl_->PinchGestureUpdate(.5f, gfx::Point());
  host_impl_->PinchGestureEnd();
  host_impl_->ScrollEnd(EndState().get());

  // Scrolling should be relative to the offset as given by the delegate.
  gfx::Vector2dF scroll_delta(0.f, 10.f);
  gfx::ScrollOffset current_offset(7.f, 8.f);

  EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
            host_impl_
                ->ScrollBegin(BeginState(gfx::Point()).get(),
                              InputHandler::TOUCHSCREEN)
                .thread);
  host_impl_->SetSynchronousInputHandlerRootScrollOffset(current_offset);

  host_impl_->ScrollBy(UpdateState(gfx::Point(), scroll_delta).get());
  EXPECT_EQ(ScrollOffsetWithDelta(current_offset, scroll_delta),
            scroll_watcher.last_set_scroll_offset());

  current_offset = gfx::ScrollOffset(42.f, 41.f);
  host_impl_->SetSynchronousInputHandlerRootScrollOffset(current_offset);
  host_impl_->ScrollBy(UpdateState(gfx::Point(), scroll_delta).get());
  EXPECT_EQ(current_offset + gfx::ScrollOffset(scroll_delta),
            scroll_watcher.last_set_scroll_offset());
  host_impl_->ScrollEnd(EndState().get());
  host_impl_->SetSynchronousInputHandlerRootScrollOffset(gfx::ScrollOffset());

  // Forces a full tree synchronization and ensures that the scroll delegate
  // sees the correct size of the new tree.
  gfx::Size new_size(42, 24);
  host_impl_->CreatePendingTree();
  host_impl_->pending_tree()->PushPageScaleFromMainThread(1.f, 1.f, 1.f);
  CreateScrollAndContentsLayers(host_impl_->pending_tree(), new_size);
  host_impl_->pending_tree()->BuildPropertyTreesForTesting();
  host_impl_->ActivateSyncTree();
  EXPECT_EQ(gfx::SizeF(new_size), scroll_watcher.scrollable_size());

  // Tear down the LayerTreeHostImpl before the InputHandlerClient.
  host_impl_.reset();
}

void CheckLayerScrollDelta(LayerImpl* layer, gfx::Vector2dF scroll_delta) {
  const gfx::Transform target_space_transform =
      layer->draw_properties().target_space_transform;
  EXPECT_TRUE(target_space_transform.IsScaleOrTranslation());
  gfx::Point translated_point;
  target_space_transform.TransformPoint(&translated_point);
  gfx::Point expected_point = gfx::Point() - ToRoundedVector2d(scroll_delta);
  EXPECT_EQ(expected_point.ToString(), translated_point.ToString());
}

TEST_F(LayerTreeHostImplTest,
       ExternalRootLayerScrollOffsetDelegationReflectedInNextDraw) {
  host_impl_->SetViewportSize(gfx::Size(10, 20));
  LayerImpl* scroll_layer = SetupScrollAndContentsLayers(gfx::Size(100, 100));
  LayerImpl* clip_layer = scroll_layer->parent()->parent();
  clip_layer->SetBounds(gfx::Size(10, 20));
  scroll_layer->SetDrawsContent(true);

  // Draw first frame to clear any pending draws and check scroll.
  DrawFrame();
  CheckLayerScrollDelta(scroll_layer, gfx::Vector2dF(0.f, 0.f));
  EXPECT_FALSE(host_impl_->active_tree()->needs_update_draw_properties());

  // Set external scroll delta on delegate and notify LayerTreeHost.
  gfx::ScrollOffset scroll_offset(10.f, 10.f);
  host_impl_->SetSynchronousInputHandlerRootScrollOffset(scroll_offset);

  // Check scroll delta reflected in layer.
  LayerTreeHostImpl::FrameData frame;
  EXPECT_EQ(DRAW_SUCCESS, PrepareToDrawFrame(&frame));
  host_impl_->DrawLayers(&frame);
  host_impl_->DidDrawAllLayers(frame);
  EXPECT_FALSE(frame.has_no_damage);
  CheckLayerScrollDelta(scroll_layer, ScrollOffsetToVector2dF(scroll_offset));
}

TEST_F(LayerTreeHostImplTest, OverscrollRoot) {
  InputHandlerScrollResult scroll_result;
  SetupScrollAndContentsLayers(gfx::Size(100, 100));
  host_impl_->SetViewportSize(gfx::Size(50, 50));
  host_impl_->active_tree()->PushPageScaleFromMainThread(1.f, 0.5f, 4.f);
  DrawFrame();
  EXPECT_EQ(gfx::Vector2dF(), host_impl_->accumulated_root_overscroll());

  // In-bounds scrolling does not affect overscroll.
  EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
            host_impl_->ScrollBegin(BeginState(gfx::Point()).get(),
                                    InputHandler::WHEEL)
                .thread);
  scroll_result = host_impl_->ScrollBy(
      UpdateState(gfx::Point(), gfx::Vector2d(0, 10)).get());
  EXPECT_TRUE(scroll_result.did_scroll);
  EXPECT_FALSE(scroll_result.did_overscroll_root);
  EXPECT_EQ(gfx::Vector2dF(), scroll_result.unused_scroll_delta);
  EXPECT_EQ(gfx::Vector2dF(), host_impl_->accumulated_root_overscroll());

  // Overscroll events are reflected immediately.
  scroll_result = host_impl_->ScrollBy(
      UpdateState(gfx::Point(), gfx::Vector2d(0, 50)).get());
  EXPECT_TRUE(scroll_result.did_scroll);
  EXPECT_TRUE(scroll_result.did_overscroll_root);
  EXPECT_EQ(gfx::Vector2dF(0, 10), scroll_result.unused_scroll_delta);
  EXPECT_EQ(gfx::Vector2dF(0, 10), host_impl_->accumulated_root_overscroll());
  EXPECT_EQ(scroll_result.accumulated_root_overscroll,
            host_impl_->accumulated_root_overscroll());

  // In-bounds scrolling resets accumulated overscroll for the scrolled axes.
  scroll_result = host_impl_->ScrollBy(
      UpdateState(gfx::Point(), gfx::Vector2d(0, -50)).get());
  EXPECT_TRUE(scroll_result.did_scroll);
  EXPECT_FALSE(scroll_result.did_overscroll_root);
  EXPECT_EQ(gfx::Vector2dF(), scroll_result.unused_scroll_delta);
  EXPECT_EQ(gfx::Vector2dF(0, 0), host_impl_->accumulated_root_overscroll());
  EXPECT_EQ(scroll_result.accumulated_root_overscroll,
            host_impl_->accumulated_root_overscroll());

  scroll_result = host_impl_->ScrollBy(
      UpdateState(gfx::Point(), gfx::Vector2d(0, -10)).get());
  EXPECT_FALSE(scroll_result.did_scroll);
  EXPECT_TRUE(scroll_result.did_overscroll_root);
  EXPECT_EQ(gfx::Vector2dF(0, -10), scroll_result.unused_scroll_delta);
  EXPECT_EQ(gfx::Vector2dF(0, -10), host_impl_->accumulated_root_overscroll());
  EXPECT_EQ(scroll_result.accumulated_root_overscroll,
            host_impl_->accumulated_root_overscroll());

  scroll_result = host_impl_->ScrollBy(
      UpdateState(gfx::Point(), gfx::Vector2d(10, 0)).get());
  EXPECT_TRUE(scroll_result.did_scroll);
  EXPECT_FALSE(scroll_result.did_overscroll_root);
  EXPECT_EQ(gfx::Vector2dF(0, 0), scroll_result.unused_scroll_delta);
  EXPECT_EQ(gfx::Vector2dF(0, -10), host_impl_->accumulated_root_overscroll());
  EXPECT_EQ(scroll_result.accumulated_root_overscroll,
            host_impl_->accumulated_root_overscroll());

  scroll_result = host_impl_->ScrollBy(
      UpdateState(gfx::Point(), gfx::Vector2d(-15, 0)).get());
  EXPECT_TRUE(scroll_result.did_scroll);
  EXPECT_TRUE(scroll_result.did_overscroll_root);
  EXPECT_EQ(gfx::Vector2dF(-5, 0), scroll_result.unused_scroll_delta);
  EXPECT_EQ(gfx::Vector2dF(-5, -10), host_impl_->accumulated_root_overscroll());
  EXPECT_EQ(scroll_result.accumulated_root_overscroll,
            host_impl_->accumulated_root_overscroll());

  scroll_result = host_impl_->ScrollBy(
      UpdateState(gfx::Point(), gfx::Vector2d(0, 60)).get());
  EXPECT_TRUE(scroll_result.did_scroll);
  EXPECT_TRUE(scroll_result.did_overscroll_root);
  EXPECT_EQ(gfx::Vector2dF(0, 10), scroll_result.unused_scroll_delta);
  EXPECT_EQ(gfx::Vector2dF(-5, 10), host_impl_->accumulated_root_overscroll());
  EXPECT_EQ(scroll_result.accumulated_root_overscroll,
            host_impl_->accumulated_root_overscroll());

  scroll_result = host_impl_->ScrollBy(
      UpdateState(gfx::Point(), gfx::Vector2d(10, -60)).get());
  EXPECT_TRUE(scroll_result.did_scroll);
  EXPECT_TRUE(scroll_result.did_overscroll_root);
  EXPECT_EQ(gfx::Vector2dF(0, -10), scroll_result.unused_scroll_delta);
  EXPECT_EQ(gfx::Vector2dF(0, -10), host_impl_->accumulated_root_overscroll());
  EXPECT_EQ(scroll_result.accumulated_root_overscroll,
            host_impl_->accumulated_root_overscroll());

  // Overscroll accumulates within the scope of ScrollBegin/ScrollEnd as long
  // as no scroll occurs.
  scroll_result = host_impl_->ScrollBy(
      UpdateState(gfx::Point(), gfx::Vector2d(0, -20)).get());
  EXPECT_FALSE(scroll_result.did_scroll);
  EXPECT_TRUE(scroll_result.did_overscroll_root);
  EXPECT_EQ(gfx::Vector2dF(0, -20), scroll_result.unused_scroll_delta);
  EXPECT_EQ(gfx::Vector2dF(0, -30), host_impl_->accumulated_root_overscroll());
  EXPECT_EQ(scroll_result.accumulated_root_overscroll,
            host_impl_->accumulated_root_overscroll());

  scroll_result = host_impl_->ScrollBy(
      UpdateState(gfx::Point(), gfx::Vector2d(0, -20)).get());
  EXPECT_FALSE(scroll_result.did_scroll);
  EXPECT_TRUE(scroll_result.did_overscroll_root);
  EXPECT_EQ(gfx::Vector2dF(0, -20), scroll_result.unused_scroll_delta);
  EXPECT_EQ(gfx::Vector2dF(0, -50), host_impl_->accumulated_root_overscroll());
  EXPECT_EQ(scroll_result.accumulated_root_overscroll,
            host_impl_->accumulated_root_overscroll());

  // Overscroll resets on valid scroll.
  scroll_result = host_impl_->ScrollBy(
      UpdateState(gfx::Point(), gfx::Vector2d(0, 10)).get());
  EXPECT_TRUE(scroll_result.did_scroll);
  EXPECT_FALSE(scroll_result.did_overscroll_root);
  EXPECT_EQ(gfx::Vector2dF(0, 0), scroll_result.unused_scroll_delta);
  EXPECT_EQ(gfx::Vector2dF(0, 0), host_impl_->accumulated_root_overscroll());
  EXPECT_EQ(scroll_result.accumulated_root_overscroll,
            host_impl_->accumulated_root_overscroll());

  scroll_result = host_impl_->ScrollBy(
      UpdateState(gfx::Point(), gfx::Vector2d(0, -20)).get());
  EXPECT_TRUE(scroll_result.did_scroll);
  EXPECT_TRUE(scroll_result.did_overscroll_root);
  EXPECT_EQ(gfx::Vector2dF(0, -10), scroll_result.unused_scroll_delta);
  EXPECT_EQ(gfx::Vector2dF(0, -10), host_impl_->accumulated_root_overscroll());
  EXPECT_EQ(scroll_result.accumulated_root_overscroll,
            host_impl_->accumulated_root_overscroll());

  host_impl_->ScrollEnd(EndState().get());
}


TEST_F(LayerTreeHostImplTest, OverscrollChildWithoutBubbling) {
  // Scroll child layers beyond their maximum scroll range and make sure root
  // overscroll does not accumulate.
  InputHandlerScrollResult scroll_result;
  gfx::Size surface_size(10, 10);
  scoped_ptr<LayerImpl> root_clip =
      LayerImpl::Create(host_impl_->active_tree(), 4);
  root_clip->SetForceRenderSurface(true);

  scoped_ptr<LayerImpl> root =
      CreateScrollableLayer(1, surface_size, root_clip.get());

  scoped_ptr<LayerImpl> grand_child =
      CreateScrollableLayer(3, surface_size, root_clip.get());

  scoped_ptr<LayerImpl> child =
      CreateScrollableLayer(2, surface_size, root_clip.get());
  LayerImpl* grand_child_layer = grand_child.get();
  child->AddChild(std::move(grand_child));

  LayerImpl* child_layer = child.get();
  root->AddChild(std::move(child));
  root_clip->AddChild(std::move(root));
  child_layer->layer_tree_impl()
      ->property_trees()
      ->scroll_tree.UpdateScrollOffsetBaseForTesting(child_layer->id(),
                                                     gfx::ScrollOffset(0, 3));
  grand_child_layer->layer_tree_impl()
      ->property_trees()
      ->scroll_tree.UpdateScrollOffsetBaseForTesting(grand_child_layer->id(),
                                                     gfx::ScrollOffset(0, 2));
  host_impl_->active_tree()->SetRootLayer(std::move(root_clip));
  host_impl_->active_tree()->DidBecomeActive();
  host_impl_->SetViewportSize(surface_size);
  SetNeedsRebuildPropertyTrees();
  DrawFrame();
  {
    gfx::Vector2d scroll_delta(0, -10);
    EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
              host_impl_->ScrollBegin(BeginState(gfx::Point()).get(),
                                      InputHandler::NON_BUBBLING_GESTURE)
                  .thread);
    scroll_result =
        host_impl_->ScrollBy(UpdateState(gfx::Point(), scroll_delta).get());
    EXPECT_TRUE(scroll_result.did_scroll);
    EXPECT_FALSE(scroll_result.did_overscroll_root);
    EXPECT_EQ(gfx::Vector2dF(), host_impl_->accumulated_root_overscroll());
    host_impl_->ScrollEnd(EndState().get());

    // The next time we scroll we should only scroll the parent, but overscroll
    // should still not reach the root layer.
    scroll_delta = gfx::Vector2d(0, -30);
    EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
              host_impl_->ScrollBegin(BeginState(gfx::Point(5, 5)).get(),
                                      InputHandler::NON_BUBBLING_GESTURE)
                  .thread);
    EXPECT_EQ(host_impl_->CurrentlyScrollingLayer(), grand_child_layer);
    EXPECT_EQ(gfx::Vector2dF(), host_impl_->accumulated_root_overscroll());
    scroll_result =
        host_impl_->ScrollBy(UpdateState(gfx::Point(), scroll_delta).get());
    EXPECT_TRUE(scroll_result.did_scroll);
    EXPECT_FALSE(scroll_result.did_overscroll_root);
    EXPECT_EQ(host_impl_->CurrentlyScrollingLayer(), child_layer);
    EXPECT_EQ(gfx::Vector2dF(), host_impl_->accumulated_root_overscroll());
    host_impl_->ScrollEnd(EndState().get());

    // After scrolling the parent, another scroll on the opposite direction
    // should scroll the child.
    scroll_delta = gfx::Vector2d(0, 70);
    EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
              host_impl_->ScrollBegin(BeginState(gfx::Point(5, 5)).get(),
                                      InputHandler::NON_BUBBLING_GESTURE)
                  .thread);
    EXPECT_EQ(host_impl_->CurrentlyScrollingLayer(), grand_child_layer);
    scroll_result =
        host_impl_->ScrollBy(UpdateState(gfx::Point(), scroll_delta).get());
    EXPECT_TRUE(scroll_result.did_scroll);
    EXPECT_FALSE(scroll_result.did_overscroll_root);
    EXPECT_EQ(host_impl_->CurrentlyScrollingLayer(), grand_child_layer);
    EXPECT_EQ(gfx::Vector2dF(), host_impl_->accumulated_root_overscroll());
    host_impl_->ScrollEnd(EndState().get());
  }
}

TEST_F(LayerTreeHostImplTest, OverscrollChildEventBubbling) {
  // When we try to scroll a non-scrollable child layer, the scroll delta
  // should be applied to one of its ancestors if possible. Overscroll should
  // be reflected only when it has bubbled up to the root scrolling layer.
  InputHandlerScrollResult scroll_result;
  SetupScrollAndContentsLayers(gfx::Size(20, 20));
  DrawFrame();
  {
    gfx::Vector2d scroll_delta(0, 8);
    EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
              host_impl_->ScrollBegin(BeginState(gfx::Point(5, 5)).get(),
                                      InputHandler::WHEEL)
                  .thread);
    scroll_result =
        host_impl_->ScrollBy(UpdateState(gfx::Point(), scroll_delta).get());
    EXPECT_TRUE(scroll_result.did_scroll);
    EXPECT_FALSE(scroll_result.did_overscroll_root);
    EXPECT_EQ(gfx::Vector2dF(), host_impl_->accumulated_root_overscroll());
    scroll_result =
        host_impl_->ScrollBy(UpdateState(gfx::Point(), scroll_delta).get());
    EXPECT_TRUE(scroll_result.did_scroll);
    EXPECT_TRUE(scroll_result.did_overscroll_root);
    EXPECT_EQ(gfx::Vector2dF(0, 6), host_impl_->accumulated_root_overscroll());
    scroll_result =
        host_impl_->ScrollBy(UpdateState(gfx::Point(), scroll_delta).get());
    EXPECT_FALSE(scroll_result.did_scroll);
    EXPECT_TRUE(scroll_result.did_overscroll_root);
    EXPECT_EQ(gfx::Vector2dF(0, 14), host_impl_->accumulated_root_overscroll());
    host_impl_->ScrollEnd(EndState().get());
  }
}

TEST_F(LayerTreeHostImplTest, OverscrollAlways) {
  InputHandlerScrollResult scroll_result;
  LayerTreeSettings settings = DefaultSettings();
  CreateHostImpl(settings, CreateOutputSurface());

  LayerImpl* scroll_layer = SetupScrollAndContentsLayers(gfx::Size(50, 50));
  LayerImpl* clip_layer = scroll_layer->parent()->parent();
  clip_layer->SetBounds(gfx::Size(50, 50));
  SetNeedsRebuildPropertyTrees();
  RebuildPropertyTrees();
  host_impl_->SetViewportSize(gfx::Size(50, 50));
  host_impl_->active_tree()->PushPageScaleFromMainThread(1.f, 0.5f, 4.f);
  DrawFrame();
  EXPECT_EQ(gfx::Vector2dF(), host_impl_->accumulated_root_overscroll());

  // Even though the layer can't scroll the overscroll still happens.
  EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
            host_impl_->ScrollBegin(BeginState(gfx::Point()).get(),
                                    InputHandler::WHEEL)
                .thread);
  scroll_result = host_impl_->ScrollBy(
      UpdateState(gfx::Point(), gfx::Vector2d(0, 10)).get());
  EXPECT_FALSE(scroll_result.did_scroll);
  EXPECT_TRUE(scroll_result.did_overscroll_root);
  EXPECT_EQ(gfx::Vector2dF(0, 10), host_impl_->accumulated_root_overscroll());
}

TEST_F(LayerTreeHostImplTest, NoOverscrollWhenNotAtEdge) {
  InputHandlerScrollResult scroll_result;
  SetupScrollAndContentsLayers(gfx::Size(200, 200));

  DrawFrame();
  {
    // Edge glow effect should be applicable only upon reaching Edges
    // of the content. unnecessary glow effect calls shouldn't be
    // called while scrolling up without reaching the edge of the content.
    EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
              host_impl_->ScrollBegin(BeginState(gfx::Point(0, 0)).get(),
                                      InputHandler::WHEEL)
                  .thread);
    scroll_result = host_impl_->ScrollBy(
        UpdateState(gfx::Point(), gfx::Vector2dF(0, 100)).get());
    EXPECT_TRUE(scroll_result.did_scroll);
    EXPECT_FALSE(scroll_result.did_overscroll_root);
    EXPECT_EQ(gfx::Vector2dF().ToString(),
              host_impl_->accumulated_root_overscroll().ToString());
    scroll_result = host_impl_->ScrollBy(
        UpdateState(gfx::Point(), gfx::Vector2dF(0, -2.30f)).get());
    EXPECT_TRUE(scroll_result.did_scroll);
    EXPECT_FALSE(scroll_result.did_overscroll_root);
    EXPECT_EQ(gfx::Vector2dF().ToString(),
              host_impl_->accumulated_root_overscroll().ToString());
    host_impl_->ScrollEnd(EndState().get());
    // unusedrootDelta should be subtracted from applied delta so that
    // unwanted glow effect calls are not called.
    EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
              host_impl_->ScrollBegin(BeginState(gfx::Point(0, 0)).get(),
                                      InputHandler::NON_BUBBLING_GESTURE)
                  .thread);
    EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
              host_impl_->FlingScrollBegin().thread);
    scroll_result = host_impl_->ScrollBy(
        UpdateState(gfx::Point(), gfx::Vector2dF(0, 20)).get());
    EXPECT_TRUE(scroll_result.did_scroll);
    EXPECT_TRUE(scroll_result.did_overscroll_root);
    EXPECT_VECTOR2DF_EQ(gfx::Vector2dF(0.000000f, 17.699997f),
                        host_impl_->accumulated_root_overscroll());

    scroll_result = host_impl_->ScrollBy(
        UpdateState(gfx::Point(), gfx::Vector2dF(0.02f, -0.01f)).get());
    EXPECT_FALSE(scroll_result.did_scroll);
    EXPECT_FALSE(scroll_result.did_overscroll_root);
    EXPECT_VECTOR2DF_EQ(gfx::Vector2dF(0.000000f, 17.699997f),
                        host_impl_->accumulated_root_overscroll());
    host_impl_->ScrollEnd(EndState().get());
    // TestCase to check  kEpsilon, which prevents minute values to trigger
    // gloweffect without reaching edge.
    EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
              host_impl_->ScrollBegin(BeginState(gfx::Point(0, 0)).get(),
                                      InputHandler::WHEEL)
                  .thread);
    scroll_result = host_impl_->ScrollBy(
        UpdateState(gfx::Point(), gfx::Vector2dF(-0.12f, 0.1f)).get());
    EXPECT_FALSE(scroll_result.did_scroll);
    EXPECT_FALSE(scroll_result.did_overscroll_root);
    EXPECT_EQ(gfx::Vector2dF().ToString(),
              host_impl_->accumulated_root_overscroll().ToString());
    host_impl_->ScrollEnd(EndState().get());
  }
}

class BlendStateCheckLayer : public LayerImpl {
 public:
  static scoped_ptr<LayerImpl> Create(LayerTreeImpl* tree_impl,
                                      int id,
                                      ResourceProvider* resource_provider) {
    return make_scoped_ptr(
        new BlendStateCheckLayer(tree_impl, id, resource_provider));
  }

  void AppendQuads(RenderPass* render_pass,
                   AppendQuadsData* append_quads_data) override {
    quads_appended_ = true;

    gfx::Rect opaque_rect;
    if (contents_opaque())
      opaque_rect = quad_rect_;
    else
      opaque_rect = opaque_content_rect_;
    gfx::Rect visible_quad_rect = quad_rect_;

    SharedQuadState* shared_quad_state =
        render_pass->CreateAndAppendSharedQuadState();
    PopulateSharedQuadState(shared_quad_state);

    TileDrawQuad* test_blending_draw_quad =
        render_pass->CreateAndAppendDrawQuad<TileDrawQuad>();
    test_blending_draw_quad->SetNew(shared_quad_state,
                                    quad_rect_,
                                    opaque_rect,
                                    visible_quad_rect,
                                    resource_id_,
                                    gfx::RectF(0.f, 0.f, 1.f, 1.f),
                                    gfx::Size(1, 1),
                                    false,
                                    false);
    test_blending_draw_quad->visible_rect = quad_visible_rect_;
    EXPECT_EQ(blend_, test_blending_draw_quad->ShouldDrawWithBlending());
    EXPECT_EQ(has_render_surface_, !!render_surface());
  }

  void SetExpectation(bool blend, bool has_render_surface) {
    blend_ = blend;
    has_render_surface_ = has_render_surface;
    quads_appended_ = false;
  }

  bool quads_appended() const { return quads_appended_; }

  void SetQuadRect(const gfx::Rect& rect) { quad_rect_ = rect; }
  void SetQuadVisibleRect(const gfx::Rect& rect) { quad_visible_rect_ = rect; }
  void SetOpaqueContentRect(const gfx::Rect& rect) {
    opaque_content_rect_ = rect;
  }

 private:
  BlendStateCheckLayer(LayerTreeImpl* tree_impl,
                       int id,
                       ResourceProvider* resource_provider)
      : LayerImpl(tree_impl, id),
        blend_(false),
        has_render_surface_(false),
        quads_appended_(false),
        quad_rect_(5, 5, 5, 5),
        quad_visible_rect_(5, 5, 5, 5),
        resource_id_(resource_provider->CreateResource(
            gfx::Size(1, 1),
            ResourceProvider::TEXTURE_HINT_IMMUTABLE,
            RGBA_8888)) {
    resource_provider->AllocateForTesting(resource_id_);
    SetBounds(gfx::Size(10, 10));
    SetDrawsContent(true);
  }

  bool blend_;
  bool has_render_surface_;
  bool quads_appended_;
  gfx::Rect quad_rect_;
  gfx::Rect opaque_content_rect_;
  gfx::Rect quad_visible_rect_;
  ResourceId resource_id_;
};

TEST_F(LayerTreeHostImplTest, BlendingOffWhenDrawingOpaqueLayers) {
  {
    scoped_ptr<LayerImpl> root =
        LayerImpl::Create(host_impl_->active_tree(), 1);
    root->SetBounds(gfx::Size(10, 10));
    root->SetDrawsContent(false);
    root->SetForceRenderSurface(true);
    host_impl_->active_tree()->SetRootLayer(std::move(root));
  }
  LayerImpl* root = host_impl_->active_tree()->root_layer();

  root->AddChild(
      BlendStateCheckLayer::Create(host_impl_->active_tree(),
                                   2,
                                   host_impl_->resource_provider()));
  BlendStateCheckLayer* layer1 =
      static_cast<BlendStateCheckLayer*>(root->children()[0].get());
  layer1->SetPosition(gfx::PointF(2.f, 2.f));

  LayerTreeHostImpl::FrameData frame;

  // Opaque layer, drawn without blending.
  layer1->SetContentsOpaque(true);
  layer1->SetExpectation(false, false);
  layer1->SetUpdateRect(gfx::Rect(layer1->bounds()));
  SetNeedsRebuildPropertyTrees();
  EXPECT_EQ(DRAW_SUCCESS, PrepareToDrawFrame(&frame));
  host_impl_->DrawLayers(&frame);
  EXPECT_TRUE(layer1->quads_appended());
  host_impl_->DidDrawAllLayers(frame);

  // Layer with translucent content and painting, so drawn with blending.
  layer1->SetContentsOpaque(false);
  layer1->SetExpectation(true, false);
  layer1->SetUpdateRect(gfx::Rect(layer1->bounds()));
  SetNeedsRebuildPropertyTrees();
  EXPECT_EQ(DRAW_SUCCESS, PrepareToDrawFrame(&frame));
  host_impl_->DrawLayers(&frame);
  EXPECT_TRUE(layer1->quads_appended());
  host_impl_->DidDrawAllLayers(frame);

  // Layer with translucent opacity, drawn with blending.
  layer1->SetContentsOpaque(true);
  layer1->SetOpacity(0.5f);
  layer1->NoteLayerPropertyChanged();
  layer1->SetExpectation(true, false);
  layer1->SetUpdateRect(gfx::Rect(layer1->bounds()));
  SetNeedsRebuildPropertyTrees();
  EXPECT_EQ(DRAW_SUCCESS, PrepareToDrawFrame(&frame));
  host_impl_->DrawLayers(&frame);
  EXPECT_TRUE(layer1->quads_appended());
  host_impl_->DidDrawAllLayers(frame);

  // Layer with translucent opacity and painting, drawn with blending.
  layer1->SetContentsOpaque(true);
  layer1->SetOpacity(0.5f);
  layer1->NoteLayerPropertyChanged();
  layer1->SetExpectation(true, false);
  layer1->SetUpdateRect(gfx::Rect(layer1->bounds()));
  SetNeedsRebuildPropertyTrees();
  EXPECT_EQ(DRAW_SUCCESS, PrepareToDrawFrame(&frame));
  host_impl_->DrawLayers(&frame);
  EXPECT_TRUE(layer1->quads_appended());
  host_impl_->DidDrawAllLayers(frame);

  layer1->AddChild(
      BlendStateCheckLayer::Create(host_impl_->active_tree(),
                                   3,
                                   host_impl_->resource_provider()));
  BlendStateCheckLayer* layer2 =
      static_cast<BlendStateCheckLayer*>(layer1->children()[0].get());
  layer2->SetPosition(gfx::PointF(4.f, 4.f));

  // 2 opaque layers, drawn without blending.
  layer1->SetContentsOpaque(true);
  layer1->SetOpacity(1.f);
  layer1->NoteLayerPropertyChanged();
  layer1->SetExpectation(false, false);
  layer1->SetUpdateRect(gfx::Rect(layer1->bounds()));
  layer2->SetContentsOpaque(true);
  layer2->SetOpacity(1.f);
  layer2->NoteLayerPropertyChanged();
  layer2->SetExpectation(false, false);
  layer2->SetUpdateRect(gfx::Rect(layer1->bounds()));
  SetNeedsRebuildPropertyTrees();
  EXPECT_EQ(DRAW_SUCCESS, PrepareToDrawFrame(&frame));
  host_impl_->DrawLayers(&frame);
  EXPECT_TRUE(layer1->quads_appended());
  EXPECT_TRUE(layer2->quads_appended());
  host_impl_->DidDrawAllLayers(frame);

  // Parent layer with translucent content, drawn with blending.
  // Child layer with opaque content, drawn without blending.
  layer1->SetContentsOpaque(false);
  layer1->SetExpectation(true, false);
  layer1->SetUpdateRect(gfx::Rect(layer1->bounds()));
  layer2->SetExpectation(false, false);
  layer2->SetUpdateRect(gfx::Rect(layer1->bounds()));
  SetNeedsRebuildPropertyTrees();
  EXPECT_EQ(DRAW_SUCCESS, PrepareToDrawFrame(&frame));
  host_impl_->DrawLayers(&frame);
  EXPECT_TRUE(layer1->quads_appended());
  EXPECT_TRUE(layer2->quads_appended());
  host_impl_->DidDrawAllLayers(frame);

  // Parent layer with translucent content but opaque painting, drawn without
  // blending.
  // Child layer with opaque content, drawn without blending.
  layer1->SetContentsOpaque(true);
  layer1->SetExpectation(false, false);
  layer1->SetUpdateRect(gfx::Rect(layer1->bounds()));
  layer2->SetExpectation(false, false);
  layer2->SetUpdateRect(gfx::Rect(layer1->bounds()));
  SetNeedsRebuildPropertyTrees();
  EXPECT_EQ(DRAW_SUCCESS, PrepareToDrawFrame(&frame));
  host_impl_->DrawLayers(&frame);
  EXPECT_TRUE(layer1->quads_appended());
  EXPECT_TRUE(layer2->quads_appended());
  host_impl_->DidDrawAllLayers(frame);

  // Parent layer with translucent opacity and opaque content. Since it has a
  // drawing child, it's drawn to a render surface which carries the opacity,
  // so it's itself drawn without blending.
  // Child layer with opaque content, drawn without blending (parent surface
  // carries the inherited opacity).
  layer1->SetContentsOpaque(true);
  layer1->SetOpacity(0.5f);
  layer1->NoteLayerPropertyChanged();
  layer1->SetForceRenderSurface(true);
  layer1->SetExpectation(false, true);
  layer1->SetUpdateRect(gfx::Rect(layer1->bounds()));
  layer2->SetExpectation(false, false);
  layer2->SetUpdateRect(gfx::Rect(layer1->bounds()));
  FakeLayerTreeHostImpl::RecursiveUpdateNumChildren(
      host_impl_->active_tree()->root_layer());
  SetNeedsRebuildPropertyTrees();
  EXPECT_EQ(DRAW_SUCCESS, PrepareToDrawFrame(&frame));
  host_impl_->DrawLayers(&frame);
  EXPECT_TRUE(layer1->quads_appended());
  EXPECT_TRUE(layer2->quads_appended());
  host_impl_->DidDrawAllLayers(frame);
  layer1->SetForceRenderSurface(false);

  // Draw again, but with child non-opaque, to make sure
  // layer1 not culled.
  layer1->SetContentsOpaque(true);
  layer1->SetOpacity(1.f);
  layer1->NoteLayerPropertyChanged();
  layer1->SetExpectation(false, false);
  layer1->SetUpdateRect(gfx::Rect(layer1->bounds()));
  layer2->SetContentsOpaque(true);
  layer2->SetOpacity(0.5f);
  layer2->NoteLayerPropertyChanged();
  layer2->SetExpectation(true, false);
  layer2->SetUpdateRect(gfx::Rect(layer1->bounds()));
  SetNeedsRebuildPropertyTrees();
  EXPECT_EQ(DRAW_SUCCESS, PrepareToDrawFrame(&frame));
  host_impl_->DrawLayers(&frame);
  EXPECT_TRUE(layer1->quads_appended());
  EXPECT_TRUE(layer2->quads_appended());
  host_impl_->DidDrawAllLayers(frame);

  // A second way of making the child non-opaque.
  layer1->SetContentsOpaque(true);
  layer1->SetOpacity(1.f);
  layer1->NoteLayerPropertyChanged();
  layer1->SetExpectation(false, false);
  layer1->SetUpdateRect(gfx::Rect(layer1->bounds()));
  layer2->SetContentsOpaque(false);
  layer2->SetOpacity(1.f);
  layer2->NoteLayerPropertyChanged();
  layer2->SetExpectation(true, false);
  layer2->SetUpdateRect(gfx::Rect(layer1->bounds()));
  SetNeedsRebuildPropertyTrees();
  EXPECT_EQ(DRAW_SUCCESS, PrepareToDrawFrame(&frame));
  host_impl_->DrawLayers(&frame);
  EXPECT_TRUE(layer1->quads_appended());
  EXPECT_TRUE(layer2->quads_appended());
  host_impl_->DidDrawAllLayers(frame);

  // And when the layer says its not opaque but is painted opaque, it is not
  // blended.
  layer1->SetContentsOpaque(true);
  layer1->SetOpacity(1.f);
  layer1->NoteLayerPropertyChanged();
  layer1->SetExpectation(false, false);
  layer1->SetUpdateRect(gfx::Rect(layer1->bounds()));
  layer2->SetContentsOpaque(true);
  layer2->SetOpacity(1.f);
  layer2->NoteLayerPropertyChanged();
  layer2->SetExpectation(false, false);
  layer2->SetUpdateRect(gfx::Rect(layer1->bounds()));
  SetNeedsRebuildPropertyTrees();
  EXPECT_EQ(DRAW_SUCCESS, PrepareToDrawFrame(&frame));
  host_impl_->DrawLayers(&frame);
  EXPECT_TRUE(layer1->quads_appended());
  EXPECT_TRUE(layer2->quads_appended());
  host_impl_->DidDrawAllLayers(frame);

  // Layer with partially opaque contents, drawn with blending.
  layer1->SetContentsOpaque(false);
  layer1->SetQuadRect(gfx::Rect(5, 5, 5, 5));
  layer1->SetQuadVisibleRect(gfx::Rect(5, 5, 5, 5));
  layer1->SetOpaqueContentRect(gfx::Rect(5, 5, 2, 5));
  layer1->SetExpectation(true, false);
  layer1->SetUpdateRect(gfx::Rect(layer1->bounds()));
  SetNeedsRebuildPropertyTrees();
  EXPECT_EQ(DRAW_SUCCESS, PrepareToDrawFrame(&frame));
  host_impl_->DrawLayers(&frame);
  EXPECT_TRUE(layer1->quads_appended());
  host_impl_->DidDrawAllLayers(frame);

  // Layer with partially opaque contents partially culled, drawn with blending.
  layer1->SetContentsOpaque(false);
  layer1->SetQuadRect(gfx::Rect(5, 5, 5, 5));
  layer1->SetQuadVisibleRect(gfx::Rect(5, 5, 5, 2));
  layer1->SetOpaqueContentRect(gfx::Rect(5, 5, 2, 5));
  layer1->SetExpectation(true, false);
  layer1->SetUpdateRect(gfx::Rect(layer1->bounds()));
  SetNeedsRebuildPropertyTrees();
  EXPECT_EQ(DRAW_SUCCESS, PrepareToDrawFrame(&frame));
  host_impl_->DrawLayers(&frame);
  EXPECT_TRUE(layer1->quads_appended());
  host_impl_->DidDrawAllLayers(frame);

  // Layer with partially opaque contents culled, drawn with blending.
  layer1->SetContentsOpaque(false);
  layer1->SetQuadRect(gfx::Rect(5, 5, 5, 5));
  layer1->SetQuadVisibleRect(gfx::Rect(7, 5, 3, 5));
  layer1->SetOpaqueContentRect(gfx::Rect(5, 5, 2, 5));
  layer1->SetExpectation(true, false);
  layer1->SetUpdateRect(gfx::Rect(layer1->bounds()));
  SetNeedsRebuildPropertyTrees();
  EXPECT_EQ(DRAW_SUCCESS, PrepareToDrawFrame(&frame));
  host_impl_->DrawLayers(&frame);
  EXPECT_TRUE(layer1->quads_appended());
  host_impl_->DidDrawAllLayers(frame);

  // Layer with partially opaque contents and translucent contents culled, drawn
  // without blending.
  layer1->SetContentsOpaque(false);
  layer1->SetQuadRect(gfx::Rect(5, 5, 5, 5));
  layer1->SetQuadVisibleRect(gfx::Rect(5, 5, 2, 5));
  layer1->SetOpaqueContentRect(gfx::Rect(5, 5, 2, 5));
  layer1->SetExpectation(false, false);
  layer1->SetUpdateRect(gfx::Rect(layer1->bounds()));
  SetNeedsRebuildPropertyTrees();
  EXPECT_EQ(DRAW_SUCCESS, PrepareToDrawFrame(&frame));
  host_impl_->DrawLayers(&frame);
  EXPECT_TRUE(layer1->quads_appended());
  host_impl_->DidDrawAllLayers(frame);
}

class LayerTreeHostImplViewportCoveredTest : public LayerTreeHostImplTest {
 protected:
  LayerTreeHostImplViewportCoveredTest() :
      gutter_quad_material_(DrawQuad::SOLID_COLOR),
      child_(NULL),
      did_activate_pending_tree_(false) {}

  scoped_ptr<OutputSurface> CreateFakeOutputSurface(bool software) {
    if (software) {
      return FakeOutputSurface::CreateSoftware(
          make_scoped_ptr(new SoftwareOutputDevice()));
    }
    return FakeOutputSurface::Create3d();
  }

  void SetupActiveTreeLayers() {
    host_impl_->active_tree()->set_background_color(SK_ColorGRAY);
    host_impl_->active_tree()->SetRootLayer(
        LayerImpl::Create(host_impl_->active_tree(), 1));
    host_impl_->active_tree()->root_layer()->SetForceRenderSurface(true);
    host_impl_->active_tree()->root_layer()->AddChild(
        BlendStateCheckLayer::Create(host_impl_->active_tree(),
                                     2,
                                     host_impl_->resource_provider()));
    child_ = static_cast<BlendStateCheckLayer*>(
        host_impl_->active_tree()->root_layer()->children()[0].get());
    child_->SetExpectation(false, false);
    child_->SetContentsOpaque(true);
  }

  // Expect no gutter rects.
  void TestLayerCoversFullViewport() {
    gfx::Rect layer_rect(viewport_size_);
    child_->SetPosition(gfx::PointF(layer_rect.origin()));
    child_->SetBounds(layer_rect.size());
    child_->SetQuadRect(gfx::Rect(layer_rect.size()));
    child_->SetQuadVisibleRect(gfx::Rect(layer_rect.size()));

    LayerTreeHostImpl::FrameData frame;
    SetNeedsRebuildPropertyTrees();
    EXPECT_EQ(DRAW_SUCCESS, PrepareToDrawFrame(&frame));
    ASSERT_EQ(1u, frame.render_passes.size());

    EXPECT_EQ(0u, CountGutterQuads(frame.render_passes[0]->quad_list));
    EXPECT_EQ(1u, frame.render_passes[0]->quad_list.size());
    ValidateTextureDrawQuads(frame.render_passes[0]->quad_list);

    VerifyQuadsExactlyCoverViewport(frame.render_passes[0]->quad_list);
    host_impl_->DidDrawAllLayers(frame);
  }

  // Expect fullscreen gutter rect.
  void SetUpEmptylayer() {
    gfx::Rect layer_rect(0, 0, 0, 0);
    child_->SetPosition(gfx::PointF(layer_rect.origin()));
    child_->SetBounds(layer_rect.size());
    child_->SetQuadRect(gfx::Rect(layer_rect.size()));
    child_->SetQuadVisibleRect(gfx::Rect(layer_rect.size()));
  }

  void VerifyEmptyLayerRenderPasses(const RenderPassList& render_passes) {
    ASSERT_EQ(1u, render_passes.size());

    EXPECT_EQ(1u, CountGutterQuads(render_passes[0]->quad_list));
    EXPECT_EQ(1u, render_passes[0]->quad_list.size());
    ValidateTextureDrawQuads(render_passes[0]->quad_list);

    VerifyQuadsExactlyCoverViewport(render_passes[0]->quad_list);
  }

  void TestEmptyLayer() {
    SetUpEmptylayer();
    LayerTreeHostImpl::FrameData frame;
    SetNeedsRebuildPropertyTrees();
    EXPECT_EQ(DRAW_SUCCESS, PrepareToDrawFrame(&frame));
    VerifyEmptyLayerRenderPasses(frame.render_passes);
    host_impl_->DidDrawAllLayers(frame);
  }

  void TestEmptyLayerWithOnDraw() {
    SetUpEmptylayer();
    gfx::Transform identity;
    gfx::Rect viewport(viewport_size_);
    bool resourceless_software_draw = true;
    SetNeedsRebuildPropertyTrees();
    host_impl_->OnDraw(identity, viewport, viewport,
                       resourceless_software_draw);
    VerifyEmptyLayerRenderPasses(last_on_draw_render_passes_);
  }

  // Expect four surrounding gutter rects.
  void SetUpLayerInMiddleOfViewport() {
    gfx::Rect layer_rect(500, 500, 200, 200);
    child_->SetPosition(gfx::PointF(layer_rect.origin()));
    child_->SetBounds(layer_rect.size());
    child_->SetQuadRect(gfx::Rect(layer_rect.size()));
    child_->SetQuadVisibleRect(gfx::Rect(layer_rect.size()));
  }

  void VerifyLayerInMiddleOfViewport(const RenderPassList& render_passes) {
    ASSERT_EQ(1u, render_passes.size());

    EXPECT_EQ(4u, CountGutterQuads(render_passes[0]->quad_list));
    EXPECT_EQ(5u, render_passes[0]->quad_list.size());
    ValidateTextureDrawQuads(render_passes[0]->quad_list);

    VerifyQuadsExactlyCoverViewport(render_passes[0]->quad_list);
  }

  void TestLayerInMiddleOfViewport() {
    SetUpLayerInMiddleOfViewport();
    LayerTreeHostImpl::FrameData frame;
    SetNeedsRebuildPropertyTrees();
    EXPECT_EQ(DRAW_SUCCESS, PrepareToDrawFrame(&frame));
    VerifyLayerInMiddleOfViewport(frame.render_passes);
    host_impl_->DidDrawAllLayers(frame);
  }

  void TestLayerInMiddleOfViewportWithOnDraw() {
    SetUpLayerInMiddleOfViewport();
    gfx::Transform identity;
    gfx::Rect viewport(viewport_size_);
    bool resourceless_software_draw = true;
    SetNeedsRebuildPropertyTrees();
    host_impl_->OnDraw(identity, viewport, viewport,
                       resourceless_software_draw);
    VerifyLayerInMiddleOfViewport(last_on_draw_render_passes_);
  }

  // Expect no gutter rects.
  void SetUpLayerIsLargerThanViewport() {
    gfx::Rect layer_rect(viewport_size_.width() + 10,
                         viewport_size_.height() + 10);
    child_->SetPosition(gfx::PointF(layer_rect.origin()));
    child_->SetBounds(layer_rect.size());
    child_->SetQuadRect(gfx::Rect(layer_rect.size()));
    child_->SetQuadVisibleRect(gfx::Rect(layer_rect.size()));
  }

  void VerifyLayerIsLargerThanViewport(const RenderPassList& render_passes) {
    ASSERT_EQ(1u, render_passes.size());

    EXPECT_EQ(0u, CountGutterQuads(render_passes[0]->quad_list));
    EXPECT_EQ(1u, render_passes[0]->quad_list.size());
    ValidateTextureDrawQuads(render_passes[0]->quad_list);
  }

  void TestLayerIsLargerThanViewport() {
    SetUpLayerIsLargerThanViewport();
    LayerTreeHostImpl::FrameData frame;
    SetNeedsRebuildPropertyTrees();
    EXPECT_EQ(DRAW_SUCCESS, PrepareToDrawFrame(&frame));
    VerifyLayerIsLargerThanViewport(frame.render_passes);
    host_impl_->DidDrawAllLayers(frame);
  }

  void TestLayerIsLargerThanViewportWithOnDraw() {
    SetUpLayerIsLargerThanViewport();
    gfx::Transform identity;
    gfx::Rect viewport(viewport_size_);
    bool resourceless_software_draw = true;
    SetNeedsRebuildPropertyTrees();
    host_impl_->OnDraw(identity, viewport, viewport,
                       resourceless_software_draw);
    VerifyLayerIsLargerThanViewport(last_on_draw_render_passes_);
  }

  void DidActivateSyncTree() override { did_activate_pending_tree_ = true; }

  void set_gutter_quad_material(DrawQuad::Material material) {
    gutter_quad_material_ = material;
  }
  void set_gutter_texture_size(const gfx::Size& gutter_texture_size) {
    gutter_texture_size_ = gutter_texture_size;
  }

 protected:
  size_t CountGutterQuads(const QuadList& quad_list) {
    size_t num_gutter_quads = 0;
    for (const auto& quad : quad_list) {
      num_gutter_quads += (quad->material == gutter_quad_material_) ? 1 : 0;
    }
    return num_gutter_quads;
  }

  void VerifyQuadsExactlyCoverViewport(const QuadList& quad_list) {
    LayerTestCommon::VerifyQuadsExactlyCoverRect(
        quad_list, gfx::Rect(DipSizeToPixelSize(viewport_size_)));
  }

  // Make sure that the texture coordinates match their expectations.
  void ValidateTextureDrawQuads(const QuadList& quad_list) {
    for (const auto& quad : quad_list) {
      if (quad->material != DrawQuad::TEXTURE_CONTENT)
        continue;
      const TextureDrawQuad* texture_quad = TextureDrawQuad::MaterialCast(quad);
      gfx::SizeF gutter_texture_size_pixels =
          gfx::ScaleSize(gfx::SizeF(gutter_texture_size_),
                         host_impl_->active_tree()->device_scale_factor());
      EXPECT_EQ(texture_quad->uv_top_left.x(),
                texture_quad->rect.x() / gutter_texture_size_pixels.width());
      EXPECT_EQ(texture_quad->uv_top_left.y(),
                texture_quad->rect.y() / gutter_texture_size_pixels.height());
      EXPECT_EQ(
          texture_quad->uv_bottom_right.x(),
          texture_quad->rect.right() / gutter_texture_size_pixels.width());
      EXPECT_EQ(
          texture_quad->uv_bottom_right.y(),
          texture_quad->rect.bottom() / gutter_texture_size_pixels.height());
    }
  }

  gfx::Size DipSizeToPixelSize(const gfx::Size& size) {
    return gfx::ScaleToRoundedSize(
        size, host_impl_->active_tree()->device_scale_factor());
  }

  DrawQuad::Material gutter_quad_material_;
  gfx::Size gutter_texture_size_;
  gfx::Size viewport_size_;
  BlendStateCheckLayer* child_;
  bool did_activate_pending_tree_;
};

TEST_F(LayerTreeHostImplViewportCoveredTest, ViewportCovered) {
  viewport_size_ = gfx::Size(1000, 1000);

  bool software = false;
  CreateHostImpl(DefaultSettings(), CreateFakeOutputSurface(software));

  host_impl_->SetViewportSize(DipSizeToPixelSize(viewport_size_));
  SetupActiveTreeLayers();
  EXPECT_SCOPED(TestLayerCoversFullViewport());
  EXPECT_SCOPED(TestEmptyLayer());
  EXPECT_SCOPED(TestLayerInMiddleOfViewport());
  EXPECT_SCOPED(TestLayerIsLargerThanViewport());
}

TEST_F(LayerTreeHostImplViewportCoveredTest, ViewportCoveredScaled) {
  viewport_size_ = gfx::Size(1000, 1000);

  bool software = false;
  CreateHostImpl(DefaultSettings(), CreateFakeOutputSurface(software));

  host_impl_->active_tree()->SetDeviceScaleFactor(2.f);
  host_impl_->SetViewportSize(DipSizeToPixelSize(viewport_size_));
  SetupActiveTreeLayers();
  EXPECT_SCOPED(TestLayerCoversFullViewport());
  EXPECT_SCOPED(TestEmptyLayer());
  EXPECT_SCOPED(TestLayerInMiddleOfViewport());
  EXPECT_SCOPED(TestLayerIsLargerThanViewport());
}

TEST_F(LayerTreeHostImplViewportCoveredTest, ActiveTreeGrowViewportInvalid) {
  viewport_size_ = gfx::Size(1000, 1000);
  skip_draw_layers_in_on_draw_ = true;  // Resourceless can't draw tiled quads.

  bool software = true;
  CreateHostImpl(DefaultSettings(), CreateFakeOutputSurface(software));

  // Pending tree to force active_tree size invalid. Not used otherwise.
  host_impl_->CreatePendingTree();
  host_impl_->SetViewportSize(DipSizeToPixelSize(viewport_size_));
  EXPECT_TRUE(host_impl_->active_tree()->ViewportSizeInvalid());

  SetupActiveTreeLayers();
  EXPECT_SCOPED(TestEmptyLayerWithOnDraw());
  EXPECT_SCOPED(TestLayerInMiddleOfViewportWithOnDraw());
  EXPECT_SCOPED(TestLayerIsLargerThanViewportWithOnDraw());
}

TEST_F(LayerTreeHostImplViewportCoveredTest, ActiveTreeShrinkViewportInvalid) {
  viewport_size_ = gfx::Size(1000, 1000);
  skip_draw_layers_in_on_draw_ = true;  // Resourceless can't draw tiled quads.

  bool software = true;
  CreateHostImpl(DefaultSettings(), CreateFakeOutputSurface(software));

  // Set larger viewport and activate it to active tree.
  host_impl_->CreatePendingTree();
  gfx::Size larger_viewport(viewport_size_.width() + 100,
                            viewport_size_.height() + 100);
  host_impl_->SetViewportSize(DipSizeToPixelSize(larger_viewport));
  EXPECT_TRUE(host_impl_->active_tree()->ViewportSizeInvalid());
  host_impl_->ActivateSyncTree();
  EXPECT_TRUE(did_activate_pending_tree_);
  EXPECT_FALSE(host_impl_->active_tree()->ViewportSizeInvalid());

  // Shrink pending tree viewport without activating.
  host_impl_->CreatePendingTree();
  host_impl_->SetViewportSize(DipSizeToPixelSize(viewport_size_));
  EXPECT_TRUE(host_impl_->active_tree()->ViewportSizeInvalid());

  SetupActiveTreeLayers();
  EXPECT_SCOPED(TestEmptyLayerWithOnDraw());
  EXPECT_SCOPED(TestLayerInMiddleOfViewportWithOnDraw());
  EXPECT_SCOPED(TestLayerIsLargerThanViewportWithOnDraw());
}

class FakeDrawableLayerImpl: public LayerImpl {
 public:
  static scoped_ptr<LayerImpl> Create(LayerTreeImpl* tree_impl, int id) {
    return make_scoped_ptr(new FakeDrawableLayerImpl(tree_impl, id));
  }
 protected:
  FakeDrawableLayerImpl(LayerTreeImpl* tree_impl, int id)
      : LayerImpl(tree_impl, id) {}
};

// Only reshape when we know we are going to draw. Otherwise, the reshape
// can leave the window at the wrong size if we never draw and the proper
// viewport size is never set.
TEST_F(LayerTreeHostImplTest, ReshapeNotCalledUntilDraw) {
  scoped_refptr<TestContextProvider> provider(TestContextProvider::Create());
  scoped_ptr<OutputSurface> output_surface(
      FakeOutputSurface::Create3d(provider));
  CreateHostImpl(DefaultSettings(), std::move(output_surface));

  scoped_ptr<LayerImpl> root =
      FakeDrawableLayerImpl::Create(host_impl_->active_tree(), 1);
  root->SetBounds(gfx::Size(10, 10));
  root->SetDrawsContent(true);
  root->SetForceRenderSurface(true);
  host_impl_->active_tree()->SetRootLayer(std::move(root));
  EXPECT_FALSE(provider->TestContext3d()->reshape_called());
  provider->TestContext3d()->clear_reshape_called();

  LayerTreeHostImpl::FrameData frame;
  host_impl_->SetViewportSize(gfx::Size(10, 10));
  host_impl_->active_tree()->SetDeviceScaleFactor(1.f);
  EXPECT_EQ(DRAW_SUCCESS, PrepareToDrawFrame(&frame));
  host_impl_->DrawLayers(&frame);
  EXPECT_TRUE(provider->TestContext3d()->reshape_called());
  EXPECT_EQ(provider->TestContext3d()->width(), 10);
  EXPECT_EQ(provider->TestContext3d()->height(), 10);
  EXPECT_EQ(provider->TestContext3d()->scale_factor(), 1.f);
  host_impl_->DidDrawAllLayers(frame);
  provider->TestContext3d()->clear_reshape_called();

  host_impl_->SetViewportSize(gfx::Size(20, 30));
  EXPECT_EQ(DRAW_SUCCESS, PrepareToDrawFrame(&frame));
  host_impl_->DrawLayers(&frame);
  EXPECT_TRUE(provider->TestContext3d()->reshape_called());
  EXPECT_EQ(provider->TestContext3d()->width(), 20);
  EXPECT_EQ(provider->TestContext3d()->height(), 30);
  EXPECT_EQ(provider->TestContext3d()->scale_factor(), 1.f);
  host_impl_->DidDrawAllLayers(frame);
  provider->TestContext3d()->clear_reshape_called();

  host_impl_->active_tree()->SetDeviceScaleFactor(2.f);
  EXPECT_EQ(DRAW_SUCCESS, PrepareToDrawFrame(&frame));
  host_impl_->DrawLayers(&frame);
  EXPECT_TRUE(provider->TestContext3d()->reshape_called());
  EXPECT_EQ(provider->TestContext3d()->width(), 20);
  EXPECT_EQ(provider->TestContext3d()->height(), 30);
  EXPECT_EQ(provider->TestContext3d()->scale_factor(), 2.f);
  host_impl_->DidDrawAllLayers(frame);
  provider->TestContext3d()->clear_reshape_called();
}

// Make sure damage tracking propagates all the way to the graphics context,
// where it should request to swap only the sub-buffer that is damaged.
TEST_F(LayerTreeHostImplTest, PartialSwapReceivesDamageRect) {
  scoped_refptr<TestContextProvider> context_provider(
      TestContextProvider::Create());
  context_provider->BindToCurrentThread();
  context_provider->TestContext3d()->set_have_post_sub_buffer(true);

  scoped_ptr<FakeOutputSurface> output_surface(
      FakeOutputSurface::Create3d(context_provider));
  FakeOutputSurface* fake_output_surface = output_surface.get();

  // This test creates its own LayerTreeHostImpl, so
  // that we can force partial swap enabled.
  LayerTreeSettings settings = DefaultSettings();
  settings.renderer_settings.partial_swap_enabled = true;
  scoped_ptr<LayerTreeHostImpl> layer_tree_host_impl =
      LayerTreeHostImpl::Create(
          settings, this, &task_runner_provider_, &stats_instrumentation_,
          &shared_bitmap_manager_, NULL, &task_graph_runner_, 0);
  layer_tree_host_impl->SetVisible(true);
  layer_tree_host_impl->InitializeRenderer(output_surface.get());
  layer_tree_host_impl->WillBeginImplFrame(
      CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE));
  layer_tree_host_impl->SetViewportSize(gfx::Size(500, 500));

  scoped_ptr<LayerImpl> root =
      FakeDrawableLayerImpl::Create(layer_tree_host_impl->active_tree(), 1);
  root->SetForceRenderSurface(true);
  scoped_ptr<LayerImpl> child =
      FakeDrawableLayerImpl::Create(layer_tree_host_impl->active_tree(), 2);
  child->SetPosition(gfx::PointF(12.f, 13.f));
  child->SetBounds(gfx::Size(14, 15));
  child->SetDrawsContent(true);
  root->SetBounds(gfx::Size(500, 500));
  root->SetDrawsContent(true);
  root->AddChild(std::move(child));
  layer_tree_host_impl->active_tree()->SetRootLayer(std::move(root));

  LayerTreeHostImpl::FrameData frame;

  // First frame, the entire screen should get swapped.
  layer_tree_host_impl->active_tree()->BuildPropertyTreesForTesting();
  EXPECT_EQ(DRAW_SUCCESS, layer_tree_host_impl->PrepareToDraw(&frame));
  layer_tree_host_impl->DrawLayers(&frame);
  layer_tree_host_impl->DidDrawAllLayers(frame);
  layer_tree_host_impl->SwapBuffers(frame);
  gfx::Rect expected_swap_rect(0, 0, 500, 500);
  EXPECT_EQ(expected_swap_rect.ToString(),
            fake_output_surface->last_swap_rect().ToString());

  // Second frame, only the damaged area should get swapped. Damage should be
  // the union of old and new child rects.
  // expected damage rect: gfx::Rect(26, 28);
  // expected swap rect: vertically flipped, with origin at bottom left corner.
  layer_tree_host_impl->active_tree()->root_layer()->children()[0]->SetPosition(
      gfx::PointF());
  layer_tree_host_impl->active_tree()
      ->root_layer()
      ->children()[0]
      ->NoteLayerPropertyChanged();
  layer_tree_host_impl->active_tree()->property_trees()->needs_rebuild = true;
  layer_tree_host_impl->active_tree()->BuildPropertyTreesForTesting();
  EXPECT_EQ(DRAW_SUCCESS, layer_tree_host_impl->PrepareToDraw(&frame));
  layer_tree_host_impl->DrawLayers(&frame);
  host_impl_->DidDrawAllLayers(frame);
  layer_tree_host_impl->SwapBuffers(frame);

  // Make sure that partial swap is constrained to the viewport dimensions
  // expected damage rect: gfx::Rect(500, 500);
  // expected swap rect: flipped damage rect, but also clamped to viewport
  expected_swap_rect = gfx::Rect(0, 500-28, 26, 28);
  EXPECT_EQ(expected_swap_rect.ToString(),
            fake_output_surface->last_swap_rect().ToString());

  layer_tree_host_impl->SetViewportSize(gfx::Size(10, 10));
  // This will damage everything.
  layer_tree_host_impl->active_tree()->root_layer()->SetBackgroundColor(
      SK_ColorBLACK);
  EXPECT_EQ(DRAW_SUCCESS, layer_tree_host_impl->PrepareToDraw(&frame));
  layer_tree_host_impl->DrawLayers(&frame);
  host_impl_->DidDrawAllLayers(frame);
  layer_tree_host_impl->SwapBuffers(frame);

  expected_swap_rect = gfx::Rect(0, 0, 10, 10);
  EXPECT_EQ(expected_swap_rect.ToString(),
            fake_output_surface->last_swap_rect().ToString());
}

TEST_F(LayerTreeHostImplTest, RootLayerDoesntCreateExtraSurface) {
  scoped_ptr<LayerImpl> root =
      FakeDrawableLayerImpl::Create(host_impl_->active_tree(), 1);
  scoped_ptr<LayerImpl> child =
      FakeDrawableLayerImpl::Create(host_impl_->active_tree(), 2);
  child->SetBounds(gfx::Size(10, 10));
  child->SetDrawsContent(true);
  root->SetBounds(gfx::Size(10, 10));
  root->SetDrawsContent(true);
  root->SetForceRenderSurface(true);
  root->AddChild(std::move(child));

  host_impl_->active_tree()->SetRootLayer(std::move(root));

  LayerTreeHostImpl::FrameData frame;

  EXPECT_EQ(DRAW_SUCCESS, PrepareToDrawFrame(&frame));
  EXPECT_EQ(1u, frame.render_surface_layer_list->size());
  EXPECT_EQ(1u, frame.render_passes.size());
  host_impl_->DidDrawAllLayers(frame);
}

class FakeLayerWithQuads : public LayerImpl {
 public:
  static scoped_ptr<LayerImpl> Create(LayerTreeImpl* tree_impl, int id) {
    return make_scoped_ptr(new FakeLayerWithQuads(tree_impl, id));
  }

  void AppendQuads(RenderPass* render_pass,
                   AppendQuadsData* append_quads_data) override {
    SharedQuadState* shared_quad_state =
        render_pass->CreateAndAppendSharedQuadState();
    PopulateSharedQuadState(shared_quad_state);

    SkColor gray = SkColorSetRGB(100, 100, 100);
    gfx::Rect quad_rect(bounds());
    gfx::Rect visible_quad_rect(quad_rect);
    SolidColorDrawQuad* my_quad =
        render_pass->CreateAndAppendDrawQuad<SolidColorDrawQuad>();
    my_quad->SetNew(
        shared_quad_state, quad_rect, visible_quad_rect, gray, false);
  }

 private:
  FakeLayerWithQuads(LayerTreeImpl* tree_impl, int id)
      : LayerImpl(tree_impl, id) {}
};

class MockContext : public TestWebGraphicsContext3D {
 public:
  MOCK_METHOD1(useProgram, void(GLuint program));
  MOCK_METHOD5(uniform4f, void(GLint location,
                               GLfloat x,
                               GLfloat y,
                               GLfloat z,
                               GLfloat w));
  MOCK_METHOD4(uniformMatrix4fv, void(GLint location,
                                      GLsizei count,
                                      GLboolean transpose,
                                      const GLfloat* value));
  MOCK_METHOD4(drawElements, void(GLenum mode,
                                  GLsizei count,
                                  GLenum type,
                                  GLintptr offset));
  MOCK_METHOD1(enable, void(GLenum cap));
  MOCK_METHOD1(disable, void(GLenum cap));
  MOCK_METHOD4(scissor, void(GLint x,
                             GLint y,
                             GLsizei width,
                             GLsizei height));
};

class MockContextHarness {
 private:
  MockContext* context_;

 public:
  explicit MockContextHarness(MockContext* context)
      : context_(context) {
    context_->set_have_post_sub_buffer(true);

    // Catch "uninteresting" calls
    EXPECT_CALL(*context_, useProgram(_))
        .Times(0);

    EXPECT_CALL(*context_, drawElements(_, _, _, _))
        .Times(0);

    // These are not asserted
    EXPECT_CALL(*context_, uniformMatrix4fv(_, _, _, _))
        .WillRepeatedly(Return());

    EXPECT_CALL(*context_, uniform4f(_, _, _, _, _))
        .WillRepeatedly(Return());

    // Any un-sanctioned calls to enable() are OK
    EXPECT_CALL(*context_, enable(_))
        .WillRepeatedly(Return());

    // Any un-sanctioned calls to disable() are OK
    EXPECT_CALL(*context_, disable(_))
        .WillRepeatedly(Return());
  }

  void MustDrawSolidQuad() {
    EXPECT_CALL(*context_, drawElements(GL_TRIANGLES, 6, GL_UNSIGNED_SHORT, 0))
        .WillOnce(Return())
        .RetiresOnSaturation();

    EXPECT_CALL(*context_, useProgram(_))
        .WillOnce(Return())
        .RetiresOnSaturation();
  }

  void MustSetScissor(int x, int y, int width, int height) {
    EXPECT_CALL(*context_, enable(GL_SCISSOR_TEST))
        .WillRepeatedly(Return());

    EXPECT_CALL(*context_, scissor(x, y, width, height))
        .Times(AtLeast(1))
        .WillRepeatedly(Return());
  }

  void MustSetNoScissor() {
    EXPECT_CALL(*context_, disable(GL_SCISSOR_TEST))
        .WillRepeatedly(Return());

    EXPECT_CALL(*context_, enable(GL_SCISSOR_TEST))
        .Times(0);

    EXPECT_CALL(*context_, scissor(_, _, _, _))
        .Times(0);
  }
};

TEST_F(LayerTreeHostImplTest, NoPartialSwap) {
  scoped_ptr<MockContext> mock_context_owned(new MockContext);
  MockContext* mock_context = mock_context_owned.get();
  MockContextHarness harness(mock_context);

  // Run test case
  LayerTreeSettings settings = DefaultSettings();
  settings.renderer_settings.partial_swap_enabled = false;
  CreateHostImpl(settings,
                 FakeOutputSurface::Create3d(std::move(mock_context_owned)));
  SetupRootLayerImpl(FakeLayerWithQuads::Create(host_impl_->active_tree(), 1));

  // Without partial swap, and no clipping, no scissor is set.
  harness.MustDrawSolidQuad();
  harness.MustSetNoScissor();
  {
    LayerTreeHostImpl::FrameData frame;
    SetNeedsRebuildPropertyTrees();
    EXPECT_EQ(DRAW_SUCCESS, PrepareToDrawFrame(&frame));
    host_impl_->DrawLayers(&frame);
    host_impl_->DidDrawAllLayers(frame);
  }
  Mock::VerifyAndClearExpectations(&mock_context);

  // Without partial swap, but a layer does clip its subtree, one scissor is
  // set.
  host_impl_->active_tree()->root_layer()->SetMasksToBounds(true);
  host_impl_->active_tree()->root_layer()->NoteLayerPropertyChanged();
  harness.MustDrawSolidQuad();
  harness.MustSetScissor(0, 0, 10, 10);
  {
    LayerTreeHostImpl::FrameData frame;
    SetNeedsRebuildPropertyTrees();
    EXPECT_EQ(DRAW_SUCCESS, PrepareToDrawFrame(&frame));
    host_impl_->DrawLayers(&frame);
    host_impl_->DidDrawAllLayers(frame);
  }
  Mock::VerifyAndClearExpectations(&mock_context);
}

TEST_F(LayerTreeHostImplTest, PartialSwap) {
  scoped_ptr<MockContext> context_owned(new MockContext);
  MockContext* mock_context = context_owned.get();
  MockContextHarness harness(mock_context);

  LayerTreeSettings settings = DefaultSettings();
  settings.renderer_settings.partial_swap_enabled = true;
  CreateHostImpl(settings,
                 FakeOutputSurface::Create3d(std::move(context_owned)));
  SetupRootLayerImpl(FakeLayerWithQuads::Create(host_impl_->active_tree(), 1));

  // The first frame is not a partially-swapped one. No scissor should be set.
  harness.MustSetNoScissor();
  harness.MustDrawSolidQuad();
  {
    LayerTreeHostImpl::FrameData frame;
    EXPECT_EQ(DRAW_SUCCESS, PrepareToDrawFrame(&frame));
    host_impl_->DrawLayers(&frame);
    host_impl_->DidDrawAllLayers(frame);
  }
  Mock::VerifyAndClearExpectations(&mock_context);

  // Damage a portion of the frame.
  host_impl_->active_tree()->root_layer()->SetUpdateRect(
      gfx::Rect(0, 0, 2, 3));

  // The second frame will be partially-swapped (the y coordinates are flipped).
  harness.MustSetScissor(0, 7, 2, 3);
  harness.MustDrawSolidQuad();
  {
    LayerTreeHostImpl::FrameData frame;
    EXPECT_EQ(DRAW_SUCCESS, PrepareToDrawFrame(&frame));
    host_impl_->DrawLayers(&frame);
    host_impl_->DidDrawAllLayers(frame);
  }
  Mock::VerifyAndClearExpectations(&mock_context);
}

static scoped_ptr<LayerTreeHostImpl> SetupLayersForOpacity(
    LayerTreeSettings settings,
    bool partial_swap,
    LayerTreeHostImplClient* client,
    TaskRunnerProvider* task_runner_provider,
    SharedBitmapManager* manager,
    TaskGraphRunner* task_graph_runner,
    RenderingStatsInstrumentation* stats_instrumentation,
    OutputSurface* output_surface) {
  settings.renderer_settings.partial_swap_enabled = partial_swap;
  scoped_ptr<LayerTreeHostImpl> my_host_impl = LayerTreeHostImpl::Create(
      settings, client, task_runner_provider, stats_instrumentation, manager,
      nullptr, task_graph_runner, 0);
  my_host_impl->SetVisible(true);
  my_host_impl->InitializeRenderer(output_surface);
  my_host_impl->WillBeginImplFrame(
      CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE));
  my_host_impl->SetViewportSize(gfx::Size(100, 100));

  /*
    Layers are created as follows:

    +--------------------+
    |                  1 |
    |  +-----------+     |
    |  |         2 |     |
    |  | +-------------------+
    |  | |   3               |
    |  | +-------------------+
    |  |           |     |
    |  +-----------+     |
    |                    |
    |                    |
    +--------------------+

    Layers 1, 2 have render surfaces
  */
  scoped_ptr<LayerImpl> root =
      LayerImpl::Create(my_host_impl->active_tree(), 1);
  scoped_ptr<LayerImpl> child =
      LayerImpl::Create(my_host_impl->active_tree(), 2);
  scoped_ptr<LayerImpl> grand_child =
      FakeLayerWithQuads::Create(my_host_impl->active_tree(), 3);

  gfx::Rect root_rect(0, 0, 100, 100);
  gfx::Rect child_rect(10, 10, 50, 50);
  gfx::Rect grand_child_rect(5, 5, 150, 150);

  root->SetForceRenderSurface(true);
  root->SetPosition(gfx::PointF(root_rect.origin()));
  root->SetBounds(root_rect.size());
  root->draw_properties().visible_layer_rect = root_rect;
  root->SetDrawsContent(false);

  child->SetPosition(gfx::PointF(child_rect.x(), child_rect.y()));
  child->SetOpacity(0.5f);
  child->SetBounds(gfx::Size(child_rect.width(), child_rect.height()));
  child->draw_properties().visible_layer_rect = child_rect;
  child->SetDrawsContent(false);
  child->SetForceRenderSurface(true);

  grand_child->SetPosition(gfx::PointF(grand_child_rect.origin()));
  grand_child->SetBounds(grand_child_rect.size());
  grand_child->draw_properties().visible_layer_rect = grand_child_rect;
  grand_child->SetDrawsContent(true);

  child->AddChild(std::move(grand_child));
  root->AddChild(std::move(child));

  my_host_impl->active_tree()->SetRootLayer(std::move(root));
  my_host_impl->active_tree()->BuildPropertyTreesForTesting();
  return my_host_impl;
}

TEST_F(LayerTreeHostImplTest, ContributingLayerEmptyScissorPartialSwap) {
  TestSharedBitmapManager shared_bitmap_manager;
  TestTaskGraphRunner task_graph_runner;
  scoped_refptr<TestContextProvider> provider(TestContextProvider::Create());
  provider->BindToCurrentThread();
  provider->TestContext3d()->set_have_post_sub_buffer(true);
  scoped_ptr<OutputSurface> output_surface(
      FakeOutputSurface::Create3d(provider));
  scoped_ptr<LayerTreeHostImpl> my_host_impl = SetupLayersForOpacity(
      DefaultSettings(), true, this, &task_runner_provider_,
      &shared_bitmap_manager, &task_graph_runner, &stats_instrumentation_,
      output_surface.get());
  {
    LayerTreeHostImpl::FrameData frame;
    EXPECT_EQ(DRAW_SUCCESS, my_host_impl->PrepareToDraw(&frame));

    // Verify all quads have been computed
    ASSERT_EQ(2U, frame.render_passes.size());
    ASSERT_EQ(1U, frame.render_passes[0]->quad_list.size());
    ASSERT_EQ(1U, frame.render_passes[1]->quad_list.size());
    EXPECT_EQ(DrawQuad::SOLID_COLOR,
              frame.render_passes[0]->quad_list.front()->material);
    EXPECT_EQ(DrawQuad::RENDER_PASS,
              frame.render_passes[1]->quad_list.front()->material);

    my_host_impl->DrawLayers(&frame);
    my_host_impl->DidDrawAllLayers(frame);
  }
}

TEST_F(LayerTreeHostImplTest, ContributingLayerEmptyScissorNoPartialSwap) {
  TestSharedBitmapManager shared_bitmap_manager;
  TestTaskGraphRunner task_graph_runner;
  scoped_refptr<TestContextProvider> provider(TestContextProvider::Create());
  provider->BindToCurrentThread();
  provider->TestContext3d()->set_have_post_sub_buffer(true);
  scoped_ptr<OutputSurface> output_surface(
      FakeOutputSurface::Create3d(provider));
  scoped_ptr<LayerTreeHostImpl> my_host_impl = SetupLayersForOpacity(
      DefaultSettings(), false, this, &task_runner_provider_,
      &shared_bitmap_manager, &task_graph_runner, &stats_instrumentation_,
      output_surface.get());
  {
    LayerTreeHostImpl::FrameData frame;
    EXPECT_EQ(DRAW_SUCCESS, my_host_impl->PrepareToDraw(&frame));

    // Verify all quads have been computed
    ASSERT_EQ(2U, frame.render_passes.size());
    ASSERT_EQ(1U, frame.render_passes[0]->quad_list.size());
    ASSERT_EQ(1U, frame.render_passes[1]->quad_list.size());
    EXPECT_EQ(DrawQuad::SOLID_COLOR,
              frame.render_passes[0]->quad_list.front()->material);
    EXPECT_EQ(DrawQuad::RENDER_PASS,
              frame.render_passes[1]->quad_list.front()->material);

    my_host_impl->DrawLayers(&frame);
    my_host_impl->DidDrawAllLayers(frame);
  }
}

TEST_F(LayerTreeHostImplTest, LayersFreeTextures) {
  scoped_ptr<TestWebGraphicsContext3D> context =
      TestWebGraphicsContext3D::Create();
  TestWebGraphicsContext3D* context3d = context.get();
  scoped_ptr<OutputSurface> output_surface(
      FakeOutputSurface::Create3d(std::move(context)));
  CreateHostImpl(DefaultSettings(), std::move(output_surface));

  scoped_ptr<LayerImpl> root_layer =
      LayerImpl::Create(host_impl_->active_tree(), 1);
  root_layer->SetBounds(gfx::Size(10, 10));
  root_layer->SetForceRenderSurface(true);

  scoped_refptr<VideoFrame> softwareFrame =
      media::VideoFrame::CreateColorFrame(
          gfx::Size(4, 4), 0x80, 0x80, 0x80, base::TimeDelta());
  FakeVideoFrameProvider provider;
  provider.set_frame(softwareFrame);
  scoped_ptr<VideoLayerImpl> video_layer = VideoLayerImpl::Create(
      host_impl_->active_tree(), 4, &provider, media::VIDEO_ROTATION_0);
  video_layer->SetBounds(gfx::Size(10, 10));
  video_layer->SetDrawsContent(true);
  root_layer->AddChild(std::move(video_layer));

  scoped_ptr<IOSurfaceLayerImpl> io_surface_layer =
      IOSurfaceLayerImpl::Create(host_impl_->active_tree(), 5);
  io_surface_layer->SetBounds(gfx::Size(10, 10));
  io_surface_layer->SetDrawsContent(true);
  io_surface_layer->SetIOSurfaceProperties(1, gfx::Size(10, 10));
  root_layer->AddChild(std::move(io_surface_layer));

  host_impl_->active_tree()->SetRootLayer(std::move(root_layer));

  EXPECT_EQ(0u, context3d->NumTextures());

  LayerTreeHostImpl::FrameData frame;
  EXPECT_EQ(DRAW_SUCCESS, PrepareToDrawFrame(&frame));
  host_impl_->DrawLayers(&frame);
  host_impl_->DidDrawAllLayers(frame);
  host_impl_->SwapBuffers(frame);

  EXPECT_GT(context3d->NumTextures(), 0u);

  // Kill the layer tree.
  host_impl_->active_tree()->SetRootLayer(
      LayerImpl::Create(host_impl_->active_tree(), 100));
  // There should be no textures left in use after.
  EXPECT_EQ(0u, context3d->NumTextures());
}

class MockDrawQuadsToFillScreenContext : public TestWebGraphicsContext3D {
 public:
  MOCK_METHOD1(useProgram, void(GLuint program));
  MOCK_METHOD4(drawElements, void(GLenum mode,
                                  GLsizei count,
                                  GLenum type,
                                  GLintptr offset));
};

TEST_F(LayerTreeHostImplTest, HasTransparentBackground) {
  scoped_ptr<MockDrawQuadsToFillScreenContext> mock_context_owned(
      new MockDrawQuadsToFillScreenContext);
  MockDrawQuadsToFillScreenContext* mock_context = mock_context_owned.get();

  // Run test case
  LayerTreeSettings settings = DefaultSettings();
  settings.renderer_settings.partial_swap_enabled = false;
  CreateHostImpl(settings,
                 FakeOutputSurface::Create3d(std::move(mock_context_owned)));
  SetupRootLayerImpl(LayerImpl::Create(host_impl_->active_tree(), 1));
  host_impl_->active_tree()->set_background_color(SK_ColorWHITE);

  // Verify one quad is drawn when transparent background set is not set.
  host_impl_->active_tree()->set_has_transparent_background(false);
  EXPECT_CALL(*mock_context, useProgram(_))
      .Times(1);
  EXPECT_CALL(*mock_context, drawElements(_, _, _, _))
      .Times(1);
  LayerTreeHostImpl::FrameData frame;
  EXPECT_EQ(DRAW_SUCCESS, PrepareToDrawFrame(&frame));
  host_impl_->DrawLayers(&frame);
  host_impl_->DidDrawAllLayers(frame);
  Mock::VerifyAndClearExpectations(&mock_context);

  // Verify no quads are drawn when transparent background is set.
  host_impl_->active_tree()->set_has_transparent_background(true);
  host_impl_->SetFullRootLayerDamage();
  EXPECT_EQ(DRAW_SUCCESS, PrepareToDrawFrame(&frame));
  host_impl_->DrawLayers(&frame);
  host_impl_->DidDrawAllLayers(frame);
  Mock::VerifyAndClearExpectations(&mock_context);
}

class LayerTreeHostImplTestWithDelegatingRenderer
    : public LayerTreeHostImplTest {
 protected:
  scoped_ptr<OutputSurface> CreateOutputSurface() override {
    return FakeOutputSurface::CreateDelegating3d();
  }

  void DrawFrameAndTestDamage(const gfx::Rect& expected_damage) {
    bool expect_to_draw = !expected_damage.IsEmpty();

    LayerTreeHostImpl::FrameData frame;
    EXPECT_EQ(DRAW_SUCCESS, PrepareToDrawFrame(&frame));

    if (!expect_to_draw) {
      // With no damage, we don't draw, and no quads are created.
      ASSERT_EQ(0u, frame.render_passes.size());
    } else {
      ASSERT_EQ(1u, frame.render_passes.size());

      // Verify the damage rect for the root render pass.
      const RenderPass* root_render_pass = frame.render_passes.back().get();
      EXPECT_EQ(expected_damage, root_render_pass->damage_rect);

      // Verify the root and child layers' quads are generated and not being
      // culled.
      ASSERT_EQ(2u, root_render_pass->quad_list.size());

      LayerImpl* child =
          host_impl_->active_tree()->root_layer()->children()[0].get();
      gfx::Rect expected_child_visible_rect(child->bounds());
      EXPECT_EQ(expected_child_visible_rect,
                root_render_pass->quad_list.front()->visible_rect);

      LayerImpl* root = host_impl_->active_tree()->root_layer();
      gfx::Rect expected_root_visible_rect(root->bounds());
      EXPECT_EQ(expected_root_visible_rect,
                root_render_pass->quad_list.ElementAt(1)->visible_rect);
    }

    host_impl_->DrawLayers(&frame);
    host_impl_->DidDrawAllLayers(frame);
    EXPECT_EQ(expect_to_draw, host_impl_->SwapBuffers(frame));
  }
};

TEST_F(LayerTreeHostImplTestWithDelegatingRenderer, FrameIncludesDamageRect) {
  scoped_ptr<SolidColorLayerImpl> root =
      SolidColorLayerImpl::Create(host_impl_->active_tree(), 1);
  root->SetPosition(gfx::PointF());
  root->SetBounds(gfx::Size(10, 10));
  root->SetDrawsContent(true);
  root->SetForceRenderSurface(true);

  // Child layer is in the bottom right corner.
  scoped_ptr<SolidColorLayerImpl> child =
      SolidColorLayerImpl::Create(host_impl_->active_tree(), 2);
  child->SetPosition(gfx::PointF(9.f, 9.f));
  child->SetBounds(gfx::Size(1, 1));
  child->SetDrawsContent(true);
  root->AddChild(std::move(child));

  host_impl_->active_tree()->SetRootLayer(std::move(root));

  // Draw a frame. In the first frame, the entire viewport should be damaged.
  gfx::Rect full_frame_damage(host_impl_->DrawViewportSize());
  DrawFrameAndTestDamage(full_frame_damage);

  // The second frame has damage that doesn't touch the child layer. Its quads
  // should still be generated.
  gfx::Rect small_damage = gfx::Rect(0, 0, 1, 1);
  host_impl_->active_tree()->root_layer()->SetUpdateRect(small_damage);
  DrawFrameAndTestDamage(small_damage);

  // The third frame should have no damage, so no quads should be generated.
  gfx::Rect no_damage;
  DrawFrameAndTestDamage(no_damage);
}

// TODO(reveman): Remove this test and the ability to prevent on demand raster
// when delegating renderer supports PictureDrawQuads. crbug.com/342121
TEST_F(LayerTreeHostImplTestWithDelegatingRenderer, PreventRasterizeOnDemand) {
  LayerTreeSettings settings = DefaultSettings();
  CreateHostImpl(settings, CreateOutputSurface());
  EXPECT_FALSE(host_impl_->GetRendererCapabilities().allow_rasterize_on_demand);
}

class GLRendererWithSetupQuadForAntialiasing : public GLRenderer {
 public:
  using GLRenderer::ShouldAntialiasQuad;
};

TEST_F(LayerTreeHostImplTest, FarAwayQuadsDontNeedAA) {
  // Due to precision issues (especially on Android), sometimes far
  // away quads can end up thinking they need AA.
  float device_scale_factor = 4.f / 3.f;
  gfx::Size root_size(2000, 1000);
  gfx::Size device_viewport_size =
      gfx::ScaleToCeiledSize(root_size, device_scale_factor);
  host_impl_->SetViewportSize(device_viewport_size);

  host_impl_->CreatePendingTree();
  host_impl_->pending_tree()->SetDeviceScaleFactor(device_scale_factor);
  host_impl_->pending_tree()->PushPageScaleFromMainThread(1.f, 1.f / 16.f,
                                                          16.f);

  scoped_ptr<LayerImpl> scoped_root =
      LayerImpl::Create(host_impl_->pending_tree(), 1);
  LayerImpl* root = scoped_root.get();
  root->SetForceRenderSurface(true);

  host_impl_->pending_tree()->SetRootLayer(std::move(scoped_root));

  scoped_ptr<LayerImpl> scoped_scrolling_layer =
      LayerImpl::Create(host_impl_->pending_tree(), 2);
  LayerImpl* scrolling_layer = scoped_scrolling_layer.get();
  root->AddChild(std::move(scoped_scrolling_layer));

  gfx::Size content_layer_bounds(100000, 100);
  scoped_refptr<FakeDisplayListRasterSource> raster_source(
      FakeDisplayListRasterSource::CreateFilled(content_layer_bounds));

  scoped_ptr<FakePictureLayerImpl> scoped_content_layer =
      FakePictureLayerImpl::CreateWithRasterSource(host_impl_->pending_tree(),
                                                   3, raster_source);
  LayerImpl* content_layer = scoped_content_layer.get();
  scrolling_layer->AddChild(std::move(scoped_content_layer));
  content_layer->SetBounds(content_layer_bounds);
  content_layer->SetDrawsContent(true);

  root->SetBounds(root_size);

  gfx::ScrollOffset scroll_offset(100000, 0);
  scrolling_layer->SetScrollClipLayer(root->id());
  scrolling_layer->layer_tree_impl()
      ->property_trees()
      ->scroll_tree.UpdateScrollOffsetBaseForTesting(scrolling_layer->id(),
                                                     scroll_offset);

  host_impl_->pending_tree()->BuildPropertyTreesForTesting();
  host_impl_->ActivateSyncTree();

  bool update_lcd_text = false;
  host_impl_->active_tree()->UpdateDrawProperties(update_lcd_text);
  ASSERT_EQ(1u, host_impl_->active_tree()->RenderSurfaceLayerList().size());

  LayerTreeHostImpl::FrameData frame;
  EXPECT_EQ(DRAW_SUCCESS, PrepareToDrawFrame(&frame));

  ASSERT_EQ(1u, frame.render_passes.size());
  ASSERT_LE(1u, frame.render_passes[0]->quad_list.size());
  const DrawQuad* quad = frame.render_passes[0]->quad_list.front();

  bool clipped = false, force_aa = false;
  gfx::QuadF device_layer_quad = MathUtil::MapQuad(
      quad->shared_quad_state->quad_to_target_transform,
      gfx::QuadF(gfx::RectF(quad->shared_quad_state->visible_quad_layer_rect)),
      &clipped);
  EXPECT_FALSE(clipped);
  bool antialiased =
      GLRendererWithSetupQuadForAntialiasing::ShouldAntialiasQuad(
          device_layer_quad, clipped, force_aa);
  EXPECT_FALSE(antialiased);

  host_impl_->DrawLayers(&frame);
  host_impl_->DidDrawAllLayers(frame);
}


class CompositorFrameMetadataTest : public LayerTreeHostImplTest {
 public:
  CompositorFrameMetadataTest()
      : swap_buffers_complete_(0) {}

  void DidSwapBuffersCompleteOnImplThread() override {
    swap_buffers_complete_++;
  }

  int swap_buffers_complete_;
};

TEST_F(CompositorFrameMetadataTest, CompositorFrameAckCountsAsSwapComplete) {
  SetupRootLayerImpl(FakeLayerWithQuads::Create(host_impl_->active_tree(), 1));
  {
    LayerTreeHostImpl::FrameData frame;
    EXPECT_EQ(DRAW_SUCCESS, PrepareToDrawFrame(&frame));
    host_impl_->DrawLayers(&frame);
    host_impl_->DidDrawAllLayers(frame);
  }
  CompositorFrameAck ack;
  host_impl_->ReclaimResources(&ack);
  host_impl_->DidSwapBuffersComplete();
  EXPECT_EQ(swap_buffers_complete_, 1);
}

class CountingSoftwareDevice : public SoftwareOutputDevice {
 public:
  CountingSoftwareDevice() : frames_began_(0), frames_ended_(0) {}

  SkCanvas* BeginPaint(const gfx::Rect& damage_rect) override {
    ++frames_began_;
    return SoftwareOutputDevice::BeginPaint(damage_rect);
  }
  void EndPaint() override {
    SoftwareOutputDevice::EndPaint();
    ++frames_ended_;
  }

  int frames_began_, frames_ended_;
};

TEST_F(LayerTreeHostImplTest, ForcedDrawToSoftwareDeviceBasicRender) {
  // No main thread evictions in resourceless software mode.
  set_reduce_memory_result(false);
  CountingSoftwareDevice* software_device = new CountingSoftwareDevice();
  EXPECT_TRUE(CreateHostImpl(
      DefaultSettings(),
      FakeOutputSurface::CreateSoftware(make_scoped_ptr(software_device))));
  host_impl_->SetViewportSize(gfx::Size(50, 50));

  SetupScrollAndContentsLayers(gfx::Size(100, 100));

  const gfx::Transform external_transform;
  const gfx::Rect external_viewport;
  const gfx::Rect external_clip;
  const bool resourceless_software_draw = true;
  host_impl_->SetExternalTilePriorityConstraints(external_viewport,
                                                 external_transform);

  EXPECT_EQ(0, software_device->frames_began_);
  EXPECT_EQ(0, software_device->frames_ended_);

  host_impl_->OnDraw(external_transform, external_viewport, external_clip,
                     resourceless_software_draw);

  EXPECT_EQ(1, software_device->frames_began_);
  EXPECT_EQ(1, software_device->frames_ended_);

  // Call another API method that is likely to hit nullptr in this mode.
  scoped_ptr<base::trace_event::TracedValue> state(
      new base::trace_event::TracedValue());
  host_impl_->ActivationStateAsValueInto(state.get());
}

TEST_F(LayerTreeHostImplTest,
       ForcedDrawToSoftwareDeviceSkipsUnsupportedLayers) {
  set_reduce_memory_result(false);
  EXPECT_TRUE(CreateHostImpl(DefaultSettings(),
                             FakeOutputSurface::CreateSoftware(
                                 make_scoped_ptr(new CountingSoftwareDevice))));

  const gfx::Transform external_transform;
  const gfx::Rect external_viewport;
  const gfx::Rect external_clip;
  const bool resourceless_software_draw = true;
  host_impl_->SetExternalTilePriorityConstraints(external_viewport,
                                                 external_transform);

  // SolidColorLayerImpl will be drawn.
  scoped_ptr<SolidColorLayerImpl> root_layer =
      SolidColorLayerImpl::Create(host_impl_->active_tree(), 1);

  // VideoLayerImpl will not be drawn.
  FakeVideoFrameProvider provider;
  scoped_ptr<VideoLayerImpl> video_layer = VideoLayerImpl::Create(
      host_impl_->active_tree(), 2, &provider, media::VIDEO_ROTATION_0);
  video_layer->SetBounds(gfx::Size(10, 10));
  video_layer->SetDrawsContent(true);
  root_layer->AddChild(std::move(video_layer));
  SetupRootLayerImpl(std::move(root_layer));

  host_impl_->OnDraw(external_transform, external_viewport, external_clip,
                     resourceless_software_draw);

  EXPECT_EQ(1u, last_on_draw_frame_->will_draw_layers.size());
  EXPECT_EQ(host_impl_->active_tree()->root_layer(),
            last_on_draw_frame_->will_draw_layers[0]);
}

// Checks that we have a non-0 default allocation if we pass a context that
// doesn't support memory management extensions.
TEST_F(LayerTreeHostImplTest, DefaultMemoryAllocation) {
  LayerTreeSettings settings = DefaultSettings();
  host_impl_ = LayerTreeHostImpl::Create(
      settings, this, &task_runner_provider_, &stats_instrumentation_,
      &shared_bitmap_manager_, &gpu_memory_buffer_manager_, &task_graph_runner_,
      0);

  output_surface_ =
      FakeOutputSurface::Create3d(TestWebGraphicsContext3D::Create());
  host_impl_->SetVisible(true);
  host_impl_->InitializeRenderer(output_surface_.get());
  EXPECT_LT(0ul, host_impl_->memory_allocation_limit_bytes());
}

TEST_F(LayerTreeHostImplTest, RequireHighResWhenVisible) {
  ASSERT_TRUE(host_impl_->active_tree());

  // RequiresHighResToDraw is set when new output surface is used.
  EXPECT_TRUE(host_impl_->RequiresHighResToDraw());

  host_impl_->ResetRequiresHighResToDraw();

  host_impl_->SetVisible(false);
  EXPECT_FALSE(host_impl_->RequiresHighResToDraw());
  host_impl_->SetVisible(true);
  EXPECT_TRUE(host_impl_->RequiresHighResToDraw());
  host_impl_->SetVisible(false);
  EXPECT_TRUE(host_impl_->RequiresHighResToDraw());

  host_impl_->ResetRequiresHighResToDraw();

  EXPECT_FALSE(host_impl_->RequiresHighResToDraw());
  host_impl_->SetVisible(true);
  EXPECT_TRUE(host_impl_->RequiresHighResToDraw());
}

TEST_F(LayerTreeHostImplTest, RequireHighResAfterGpuRasterizationToggles) {
  ASSERT_TRUE(host_impl_->active_tree());
  EXPECT_FALSE(host_impl_->use_gpu_rasterization());

  // RequiresHighResToDraw is set when new output surface is used.
  EXPECT_TRUE(host_impl_->RequiresHighResToDraw());

  host_impl_->ResetRequiresHighResToDraw();

  host_impl_->SetContentIsSuitableForGpuRasterization(true);
  host_impl_->SetHasGpuRasterizationTrigger(false);
  host_impl_->UpdateTreeResourcesForGpuRasterizationIfNeeded();
  EXPECT_FALSE(host_impl_->RequiresHighResToDraw());
  host_impl_->SetHasGpuRasterizationTrigger(true);
  host_impl_->UpdateTreeResourcesForGpuRasterizationIfNeeded();
  EXPECT_TRUE(host_impl_->RequiresHighResToDraw());
  host_impl_->SetHasGpuRasterizationTrigger(false);
  host_impl_->UpdateTreeResourcesForGpuRasterizationIfNeeded();
  EXPECT_TRUE(host_impl_->RequiresHighResToDraw());

  host_impl_->ResetRequiresHighResToDraw();

  EXPECT_FALSE(host_impl_->RequiresHighResToDraw());
  host_impl_->SetHasGpuRasterizationTrigger(true);
  host_impl_->UpdateTreeResourcesForGpuRasterizationIfNeeded();
  EXPECT_TRUE(host_impl_->RequiresHighResToDraw());
}

class LayerTreeHostImplTestPrepareTiles : public LayerTreeHostImplTest {
 public:
  void SetUp() override {
    fake_host_impl_ =
        new FakeLayerTreeHostImpl(LayerTreeSettings(), &task_runner_provider_,
                                  &shared_bitmap_manager_, &task_graph_runner_);
    host_impl_.reset(fake_host_impl_);
    output_surface_ = CreateOutputSurface();
    host_impl_->SetVisible(true);
    host_impl_->InitializeRenderer(output_surface_.get());
    host_impl_->SetViewportSize(gfx::Size(10, 10));
  }

  FakeLayerTreeHostImpl* fake_host_impl_;
};

TEST_F(LayerTreeHostImplTestPrepareTiles, PrepareTilesWhenInvisible) {
  EXPECT_TRUE(fake_host_impl_->prepare_tiles_needed());
  host_impl_->SetVisible(false);
  EXPECT_FALSE(fake_host_impl_->prepare_tiles_needed());
  host_impl_->SetVisible(true);
  EXPECT_TRUE(fake_host_impl_->prepare_tiles_needed());
}

TEST_F(LayerTreeHostImplTest, UIResourceManagement) {
  scoped_ptr<TestWebGraphicsContext3D> context =
      TestWebGraphicsContext3D::Create();
  TestWebGraphicsContext3D* context3d = context.get();
  scoped_ptr<FakeOutputSurface> output_surface = FakeOutputSurface::Create3d();
  CreateHostImpl(DefaultSettings(), std::move(output_surface));

  EXPECT_EQ(0u, context3d->NumTextures());

  UIResourceId ui_resource_id = 1;
  bool is_opaque = false;
  UIResourceBitmap bitmap(gfx::Size(1, 1), is_opaque);
  host_impl_->CreateUIResource(ui_resource_id, bitmap);
  EXPECT_EQ(1u, context3d->NumTextures());
  ResourceId id1 = host_impl_->ResourceIdForUIResource(ui_resource_id);
  EXPECT_NE(0u, id1);

  // Multiple requests with the same id is allowed.  The previous texture is
  // deleted.
  host_impl_->CreateUIResource(ui_resource_id, bitmap);
  EXPECT_EQ(1u, context3d->NumTextures());
  ResourceId id2 = host_impl_->ResourceIdForUIResource(ui_resource_id);
  EXPECT_NE(0u, id2);
  EXPECT_NE(id1, id2);

  // Deleting invalid UIResourceId is allowed and does not change state.
  host_impl_->DeleteUIResource(-1);
  EXPECT_EQ(1u, context3d->NumTextures());

  // Should return zero for invalid UIResourceId.  Number of textures should
  // not change.
  EXPECT_EQ(0u, host_impl_->ResourceIdForUIResource(-1));
  EXPECT_EQ(1u, context3d->NumTextures());

  host_impl_->DeleteUIResource(ui_resource_id);
  EXPECT_EQ(0u, host_impl_->ResourceIdForUIResource(ui_resource_id));
  EXPECT_EQ(0u, context3d->NumTextures());

  // Should not change state for multiple deletion on one UIResourceId
  host_impl_->DeleteUIResource(ui_resource_id);
  EXPECT_EQ(0u, context3d->NumTextures());
}

TEST_F(LayerTreeHostImplTest, CreateETC1UIResource) {
  scoped_ptr<TestWebGraphicsContext3D> context =
      TestWebGraphicsContext3D::Create();
  TestWebGraphicsContext3D* context3d = context.get();
  CreateHostImpl(DefaultSettings(), FakeOutputSurface::Create3d());

  EXPECT_EQ(0u, context3d->NumTextures());

  gfx::Size size(4, 4);
  // SkImageInfo has no support for ETC1.  The |info| below contains the right
  // total pixel size for the bitmap but not the right height and width.  The
  // correct width/height are passed directly to UIResourceBitmap.
  SkImageInfo info =
      SkImageInfo::Make(4, 2, kAlpha_8_SkColorType, kPremul_SkAlphaType);
  skia::RefPtr<SkPixelRef> pixel_ref =
      skia::AdoptRef(SkMallocPixelRef::NewAllocate(info, 0, 0));
  pixel_ref->setImmutable();
  UIResourceBitmap bitmap(pixel_ref, size);
  UIResourceId ui_resource_id = 1;
  host_impl_->CreateUIResource(ui_resource_id, bitmap);
  EXPECT_EQ(1u, context3d->NumTextures());
  ResourceId id1 = host_impl_->ResourceIdForUIResource(ui_resource_id);
  EXPECT_NE(0u, id1);
}

void ShutdownReleasesContext_Callback(scoped_ptr<CopyOutputResult> result) {
}

TEST_F(LayerTreeHostImplTest, ShutdownReleasesContext) {
  scoped_refptr<TestContextProvider> context_provider =
      TestContextProvider::Create();

  CreateHostImpl(DefaultSettings(),
                 FakeOutputSurface::Create3d(context_provider));

  SetupRootLayerImpl(LayerImpl::Create(host_impl_->active_tree(), 1));

  std::vector<scoped_ptr<CopyOutputRequest>> requests;
  requests.push_back(CopyOutputRequest::CreateRequest(
      base::Bind(&ShutdownReleasesContext_Callback)));

  LayerImpl* root = host_impl_->active_tree()->root_layer();
  root->PassCopyRequests(&requests);

  LayerTreeHostImpl::FrameData frame;
  EXPECT_EQ(DRAW_SUCCESS, PrepareToDrawFrame(&frame));
  host_impl_->DrawLayers(&frame);
  host_impl_->DidDrawAllLayers(frame);

  // The CopyOutputResult's callback has a ref on the ContextProvider and a
  // texture in a texture mailbox.
  EXPECT_FALSE(context_provider->HasOneRef());
  EXPECT_EQ(1u, context_provider->TestContext3d()->NumTextures());

  host_impl_ = nullptr;

  // The CopyOutputResult's callback was cancelled, the CopyOutputResult
  // released, and the texture deleted.
  EXPECT_TRUE(context_provider->HasOneRef());
  EXPECT_EQ(0u, context_provider->TestContext3d()->NumTextures());
}

TEST_F(LayerTreeHostImplTest, TouchFlingShouldNotBubble) {
  // When flinging via touch, only the child should scroll (we should not
  // bubble).
  gfx::Size surface_size(10, 10);
  gfx::Size content_size(20, 20);
  scoped_ptr<LayerImpl> root_ptr =
      LayerImpl::Create(host_impl_->active_tree(), 4);
  scoped_ptr<LayerImpl> root_clip =
      LayerImpl::Create(host_impl_->active_tree(), 3);
  root_clip->SetForceRenderSurface(true);

  scoped_ptr<LayerImpl> root_scroll =
      CreateScrollableLayer(1, content_size, root_clip.get());
  root_scroll->SetIsContainerForFixedPositionLayers(true);
  scoped_ptr<LayerImpl> child =
      CreateScrollableLayer(2, content_size, root_clip.get());

  root_scroll->AddChild(std::move(child));
  int root_id = root_scroll->id();
  root_clip->AddChild(std::move(root_scroll));
  root_ptr->AddChild(std::move(root_clip));

  host_impl_->SetViewportSize(surface_size);
  host_impl_->active_tree()->SetRootLayer(std::move(root_ptr));
  host_impl_->active_tree()->SetViewportLayersFromIds(Layer::INVALID_ID, 4, 1,
                                                      Layer::INVALID_ID);
  host_impl_->active_tree()->DidBecomeActive();
  SetNeedsRebuildPropertyTrees();
  DrawFrame();
  {
    EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
              host_impl_
                  ->ScrollBegin(BeginState(gfx::Point()).get(),
                                InputHandler::TOUCHSCREEN)
                  .thread);

    EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
              host_impl_->FlingScrollBegin().thread);

    gfx::Vector2d scroll_delta(0, 100);
    host_impl_->ScrollBy(UpdateState(gfx::Point(), scroll_delta).get());
    host_impl_->ScrollBy(UpdateState(gfx::Point(), scroll_delta).get());

    host_impl_->ScrollEnd(EndState().get());

    scoped_ptr<ScrollAndScaleSet> scroll_info =
        host_impl_->ProcessScrollDeltas();

    // Only the child should have scrolled.
    ASSERT_EQ(1u, scroll_info->scrolls.size());
    ExpectNone(*scroll_info.get(), root_id);
  }
}

TEST_F(LayerTreeHostImplTest, TouchFlingShouldContinueScrollingCurrentLayer) {
  // Scroll a child layer beyond its maximum scroll range and make sure the
  // the scroll doesn't bubble up to the parent layer.
  gfx::Size surface_size(10, 10);
  scoped_ptr<LayerImpl> root = LayerImpl::Create(host_impl_->active_tree(), 1);
  root->SetForceRenderSurface(true);
  scoped_ptr<LayerImpl> root_scrolling =
      CreateScrollableLayer(2, surface_size, root.get());

  scoped_ptr<LayerImpl> grand_child =
      CreateScrollableLayer(4, surface_size, root.get());
  grand_child->layer_tree_impl()
      ->property_trees()
      ->scroll_tree.UpdateScrollOffsetBaseForTesting(grand_child->id(),
                                                     gfx::ScrollOffset(0, 2));

  scoped_ptr<LayerImpl> child =
      CreateScrollableLayer(3, surface_size, root.get());
  child->layer_tree_impl()
      ->property_trees()
      ->scroll_tree.UpdateScrollOffsetBaseForTesting(child->id(),
                                                     gfx::ScrollOffset(0, 4));
  child->AddChild(std::move(grand_child));

  root_scrolling->AddChild(std::move(child));
  root->AddChild(std::move(root_scrolling));
  host_impl_->active_tree()->SetRootLayer(std::move(root));
  host_impl_->active_tree()->DidBecomeActive();
  host_impl_->SetViewportSize(surface_size);
  SetNeedsRebuildPropertyTrees();
  DrawFrame();
  {
    scoped_ptr<ScrollAndScaleSet> scroll_info;
    LayerImpl* child =
        host_impl_->active_tree()->root_layer()->children()[0]->children()
            [0].get();
    LayerImpl* grand_child = child->children()[0].get();

    gfx::Vector2d scroll_delta(0, -2);
    EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
              host_impl_
                  ->ScrollBegin(BeginState(gfx::Point()).get(),
                                InputHandler::TOUCHSCREEN)
                  .thread);
    EXPECT_TRUE(
        host_impl_->ScrollBy(UpdateState(gfx::Point(), scroll_delta).get())
            .did_scroll);

    // The grand child should have scrolled up to its limit.
    scroll_info = host_impl_->ProcessScrollDeltas();
    ASSERT_EQ(1u, scroll_info->scrolls.size());
    EXPECT_TRUE(
        ScrollInfoContains(*scroll_info, grand_child->id(), scroll_delta));
    EXPECT_EQ(host_impl_->CurrentlyScrollingLayer(), grand_child);

    // The locked scrolling layer should remain set as the grand child.
    EXPECT_FALSE(
        host_impl_->ScrollBy(UpdateState(gfx::Point(), scroll_delta).get())
            .did_scroll);
    scroll_info = host_impl_->ProcessScrollDeltas();
    ASSERT_EQ(1u, scroll_info->scrolls.size());
    EXPECT_TRUE(
        ScrollInfoContains(*scroll_info, grand_child->id(), scroll_delta));
    ExpectNone(*scroll_info, child->id());
    EXPECT_EQ(host_impl_->CurrentlyScrollingLayer(), grand_child);

    EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
              host_impl_->FlingScrollBegin().thread);
    EXPECT_FALSE(
        host_impl_->ScrollBy(UpdateState(gfx::Point(), scroll_delta).get())
            .did_scroll);
    EXPECT_EQ(host_impl_->CurrentlyScrollingLayer(), grand_child);

    // The child should not have scrolled.
    scroll_info = host_impl_->ProcessScrollDeltas();
    ASSERT_EQ(1u, scroll_info->scrolls.size());
    EXPECT_TRUE(
        ScrollInfoContains(*scroll_info, grand_child->id(), scroll_delta));
    ExpectNone(*scroll_info, child->id());

    // As the locked layer is at it's limit, no further scrolling can occur.
    EXPECT_FALSE(
        host_impl_->ScrollBy(UpdateState(gfx::Point(), scroll_delta).get())
            .did_scroll);
    EXPECT_EQ(host_impl_->CurrentlyScrollingLayer(), grand_child);
    host_impl_->ScrollEnd(EndState().get());
  }
}

TEST_F(LayerTreeHostImplTest, WheelFlingShouldntBubble) {
  // When flinging via wheel, we shouldn't bubble.
  gfx::Size surface_size(10, 10);
  gfx::Size content_size(20, 20);
  scoped_ptr<LayerImpl> root_clip =
      LayerImpl::Create(host_impl_->active_tree(), 3);
  root_clip->SetForceRenderSurface(true);
  scoped_ptr<LayerImpl> root_scroll =
      CreateScrollableLayer(1, content_size, root_clip.get());
  int root_scroll_id = root_scroll->id();
  scoped_ptr<LayerImpl> child =
      CreateScrollableLayer(2, content_size, root_clip.get());

  root_scroll->AddChild(std::move(child));
  root_clip->AddChild(std::move(root_scroll));

  host_impl_->SetViewportSize(surface_size);
  host_impl_->active_tree()->SetRootLayer(std::move(root_clip));
  host_impl_->active_tree()->DidBecomeActive();
  SetNeedsRebuildPropertyTrees();
  DrawFrame();
  {
    EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
              host_impl_->ScrollBegin(BeginState(gfx::Point()).get(),
                                      InputHandler::WHEEL)
                  .thread);

    EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
              host_impl_->FlingScrollBegin().thread);

    gfx::Vector2d scroll_delta(0, 100);
    host_impl_->ScrollBy(UpdateState(gfx::Point(), scroll_delta).get());
    host_impl_->ScrollBy(UpdateState(gfx::Point(), scroll_delta).get());

    host_impl_->ScrollEnd(EndState().get());

    scoped_ptr<ScrollAndScaleSet> scroll_info =
        host_impl_->ProcessScrollDeltas();

    // The root shouldn't have scrolled.
    ASSERT_EQ(1u, scroll_info->scrolls.size());
    ExpectNone(*scroll_info.get(), root_scroll_id);
  }
}

TEST_F(LayerTreeHostImplTest, ScrollUnknownNotOnAncestorChain) {
  // If we ray cast a scroller that is not on the first layer's ancestor chain,
  // we should return SCROLL_UNKNOWN.
  gfx::Size content_size(100, 100);
  SetupScrollAndContentsLayers(content_size);

  int scroll_layer_id = 2;
  LayerImpl* scroll_layer =
      host_impl_->active_tree()->LayerById(scroll_layer_id);
  scroll_layer->SetDrawsContent(true);

  int page_scale_layer_id = 5;
  LayerImpl* page_scale_layer =
      host_impl_->active_tree()->LayerById(page_scale_layer_id);

  int occluder_layer_id = 6;
  scoped_ptr<LayerImpl> occluder_layer =
      LayerImpl::Create(host_impl_->active_tree(), occluder_layer_id);
  occluder_layer->SetDrawsContent(true);
  occluder_layer->SetBounds(content_size);
  occluder_layer->SetPosition(gfx::PointF());

  // The parent of the occluder is *above* the scroller.
  page_scale_layer->AddChild(std::move(occluder_layer));

  SetNeedsRebuildPropertyTrees();
  DrawFrame();

  InputHandler::ScrollStatus status = host_impl_->ScrollBegin(
      BeginState(gfx::Point()).get(), InputHandler::WHEEL);
  EXPECT_EQ(InputHandler::SCROLL_UNKNOWN, status.thread);
  EXPECT_EQ(MainThreadScrollingReason::kFailedHitTest,
            status.main_thread_scrolling_reasons);
}

TEST_F(LayerTreeHostImplTest, ScrollUnknownScrollAncestorMismatch) {
  // If we ray cast a scroller this is on the first layer's ancestor chain, but
  // is not the first scroller we encounter when walking up from the layer, we
  // should also return SCROLL_UNKNOWN.
  gfx::Size content_size(100, 100);
  SetupScrollAndContentsLayers(content_size);

  int scroll_layer_id = 2;
  LayerImpl* scroll_layer =
      host_impl_->active_tree()->LayerById(scroll_layer_id);
  scroll_layer->SetDrawsContent(true);

  int occluder_layer_id = 6;
  scoped_ptr<LayerImpl> occluder_layer =
      LayerImpl::Create(host_impl_->active_tree(), occluder_layer_id);
  occluder_layer->SetDrawsContent(true);
  occluder_layer->SetBounds(content_size);
  occluder_layer->SetPosition(gfx::PointF(-10.f, -10.f));

  int child_scroll_clip_layer_id = 7;
  scoped_ptr<LayerImpl> child_scroll_clip =
      LayerImpl::Create(host_impl_->active_tree(), child_scroll_clip_layer_id);

  int child_scroll_layer_id = 8;
  scoped_ptr<LayerImpl> child_scroll = CreateScrollableLayer(
      child_scroll_layer_id, content_size, child_scroll_clip.get());

  child_scroll->SetPosition(gfx::PointF(10.f, 10.f));

  child_scroll->AddChild(std::move(occluder_layer));
  child_scroll_clip->AddChild(std::move(child_scroll));
  scroll_layer->AddChild(std::move(child_scroll_clip));

  SetNeedsRebuildPropertyTrees();
  DrawFrame();

  InputHandler::ScrollStatus status = host_impl_->ScrollBegin(
      BeginState(gfx::Point()).get(), InputHandler::WHEEL);
  EXPECT_EQ(InputHandler::SCROLL_UNKNOWN, status.thread);
  EXPECT_EQ(MainThreadScrollingReason::kFailedHitTest,
            status.main_thread_scrolling_reasons);
}

TEST_F(LayerTreeHostImplTest, NotScrollInvisibleScroller) {
  gfx::Size content_size(100, 100);
  SetupScrollAndContentsLayers(content_size);

  LayerImpl* root = host_impl_->active_tree()->LayerById(1);

  int scroll_layer_id = 2;
  LayerImpl* scroll_layer =
      host_impl_->active_tree()->LayerById(scroll_layer_id);

  int child_scroll_layer_id = 7;
  scoped_ptr<LayerImpl> child_scroll =
      CreateScrollableLayer(child_scroll_layer_id, content_size, root);
  child_scroll->SetDrawsContent(false);

  scroll_layer->AddChild(std::move(child_scroll));

  SetNeedsRebuildPropertyTrees();
  DrawFrame();

  // We should not have scrolled |child_scroll| even though we technically "hit"
  // it. The reason for this is that if the scrolling the scroll would not move
  // any layer that is a drawn RSLL member, then we can ignore the hit.
  //
  // Why SCROLL_STARTED? In this case, it's because we've bubbled out and
  // started scrolling the inner viewport.
  EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
            host_impl_->ScrollBegin(BeginState(gfx::Point()).get(),
                                    InputHandler::WHEEL)
                .thread);

  EXPECT_EQ(2, host_impl_->CurrentlyScrollingLayer()->id());
}

TEST_F(LayerTreeHostImplTest, ScrollInvisibleScrollerWithVisibleDescendent) {
  gfx::Size content_size(100, 100);
  SetupScrollAndContentsLayers(content_size);

  LayerImpl* root = host_impl_->active_tree()->LayerById(1);
  LayerImpl* root_scroll_layer = host_impl_->active_tree()->LayerById(2);

  scoped_ptr<LayerImpl> invisible_scroll_layer =
      CreateScrollableLayer(7, content_size, root);
  invisible_scroll_layer->SetDrawsContent(false);

  scoped_ptr<LayerImpl> child_layer =
      LayerImpl::Create(host_impl_->active_tree(), 8);
  child_layer->SetDrawsContent(false);

  scoped_ptr<LayerImpl> grand_child_layer =
      LayerImpl::Create(host_impl_->active_tree(), 9);
  grand_child_layer->SetDrawsContent(true);
  grand_child_layer->SetBounds(content_size);
  // Move the grand child so it's not hit by our test point.
  grand_child_layer->SetPosition(gfx::PointF(10.f, 10.f));

  child_layer->AddChild(std::move(grand_child_layer));
  invisible_scroll_layer->AddChild(std::move(child_layer));
  root_scroll_layer->AddChild(std::move(invisible_scroll_layer));

  SetNeedsRebuildPropertyTrees();
  DrawFrame();

  // We should have scrolled |invisible_scroll_layer| as it was hit and it has
  // a descendant which is a drawn RSLL member.
  EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
            host_impl_->ScrollBegin(BeginState(gfx::Point()).get(),
                                    InputHandler::WHEEL)
                .thread);

  EXPECT_EQ(7, host_impl_->CurrentlyScrollingLayer()->id());
}

TEST_F(LayerTreeHostImplTest, ScrollInvisibleScrollerWithVisibleScrollChild) {
  // This test case is very similar to the one above with one key difference:
  // the invisible scroller has a scroll child that is indeed draw contents.
  // If we attempt to initiate a gesture scroll off of the visible scroll child
  // we should still start the scroll child.
  gfx::Size content_size(100, 100);
  SetupScrollAndContentsLayers(content_size);

  LayerImpl* root = host_impl_->active_tree()->LayerById(1);

  int scroll_layer_id = 2;
  LayerImpl* scroll_layer =
      host_impl_->active_tree()->LayerById(scroll_layer_id);

  int scroll_child_id = 6;
  scoped_ptr<LayerImpl> scroll_child =
      LayerImpl::Create(host_impl_->active_tree(), scroll_child_id);
  scroll_child->SetDrawsContent(true);
  scroll_child->SetBounds(content_size);
  // Move the scroll child so it's not hit by our test point.
  scroll_child->SetPosition(gfx::PointF(10.f, 10.f));

  int invisible_scroll_layer_id = 7;
  scoped_ptr<LayerImpl> invisible_scroll =
      CreateScrollableLayer(invisible_scroll_layer_id, content_size, root);
  invisible_scroll->SetDrawsContent(false);

  int container_id = 8;
  scoped_ptr<LayerImpl> container =
      LayerImpl::Create(host_impl_->active_tree(), container_id);

  scoped_ptr<std::set<LayerImpl*>> scroll_children(new std::set<LayerImpl*>);
  scroll_children->insert(scroll_child.get());
  invisible_scroll->SetScrollChildren(scroll_children.release());

  scroll_child->SetScrollParent(invisible_scroll.get());

  container->AddChild(std::move(invisible_scroll));
  container->AddChild(std::move(scroll_child));

  scroll_layer->AddChild(std::move(container));

  SetNeedsRebuildPropertyTrees();
  DrawFrame();

  // We should have scrolled |child_scroll| even though it is invisible.
  // The reason for this is that if the scrolling the scroll would move a layer
  // that is a drawn RSLL member, then we should accept this hit.
  EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
            host_impl_->ScrollBegin(BeginState(gfx::Point()).get(),
                                    InputHandler::WHEEL)
                .thread);

  EXPECT_EQ(7, host_impl_->CurrentlyScrollingLayer()->id());
}

// Make sure LatencyInfo carried by LatencyInfoSwapPromise are passed
// to CompositorFrameMetadata after SwapBuffers();
TEST_F(LayerTreeHostImplTest, LatencyInfoPassedToCompositorFrameMetadata) {
  scoped_ptr<SolidColorLayerImpl> root =
      SolidColorLayerImpl::Create(host_impl_->active_tree(), 1);
  root->SetPosition(gfx::PointF());
  root->SetBounds(gfx::Size(10, 10));
  root->SetDrawsContent(true);
  root->SetForceRenderSurface(true);

  host_impl_->active_tree()->SetRootLayer(std::move(root));

  FakeOutputSurface* fake_output_surface =
      static_cast<FakeOutputSurface*>(host_impl_->output_surface());

  const std::vector<ui::LatencyInfo>& metadata_latency_before =
      fake_output_surface->last_sent_frame().metadata.latency_info;
  EXPECT_TRUE(metadata_latency_before.empty());

  ui::LatencyInfo latency_info;
  latency_info.AddLatencyNumber(
      ui::INPUT_EVENT_LATENCY_BEGIN_RWH_COMPONENT, 0, 0);
  scoped_ptr<SwapPromise> swap_promise(
      new LatencyInfoSwapPromise(latency_info));
  host_impl_->active_tree()->QueuePinnedSwapPromise(std::move(swap_promise));
  host_impl_->SetNeedsRedraw();

  gfx::Rect full_frame_damage(host_impl_->DrawViewportSize());
  LayerTreeHostImpl::FrameData frame;
  EXPECT_EQ(DRAW_SUCCESS, PrepareToDrawFrame(&frame));
  host_impl_->DrawLayers(&frame);
  host_impl_->DidDrawAllLayers(frame);
  EXPECT_TRUE(host_impl_->SwapBuffers(frame));

  const std::vector<ui::LatencyInfo>& metadata_latency_after =
      fake_output_surface->last_sent_frame().metadata.latency_info;
  EXPECT_EQ(1u, metadata_latency_after.size());
  EXPECT_TRUE(metadata_latency_after[0].FindLatency(
      ui::INPUT_EVENT_LATENCY_BEGIN_RWH_COMPONENT, 0, NULL));
}

TEST_F(LayerTreeHostImplTest, SelectionBoundsPassedToCompositorFrameMetadata) {
  int root_layer_id = 1;
  scoped_ptr<SolidColorLayerImpl> root =
      SolidColorLayerImpl::Create(host_impl_->active_tree(), root_layer_id);
  root->SetPosition(gfx::PointF());
  root->SetBounds(gfx::Size(10, 10));
  root->SetDrawsContent(true);
  root->SetForceRenderSurface(true);

  host_impl_->active_tree()->SetRootLayer(std::move(root));

  // Ensure the default frame selection bounds are empty.
  FakeOutputSurface* fake_output_surface =
      static_cast<FakeOutputSurface*>(host_impl_->output_surface());
  const ViewportSelection& selection_before =
      fake_output_surface->last_sent_frame().metadata.selection;
  EXPECT_EQ(ViewportSelectionBound(), selection_before.start);
  EXPECT_EQ(ViewportSelectionBound(), selection_before.end);

  // Plumb the layer-local selection bounds.
  gfx::Point selection_top(5, 0);
  gfx::Point selection_bottom(5, 5);
  LayerSelection selection;
  selection.start.type = SELECTION_BOUND_CENTER;
  selection.start.layer_id = root_layer_id;
  selection.start.edge_bottom = selection_bottom;
  selection.start.edge_top = selection_top;
  selection.end = selection.start;
  host_impl_->active_tree()->RegisterSelection(selection);

  // Trigger a draw-swap sequence.
  host_impl_->SetNeedsRedraw();

  gfx::Rect full_frame_damage(host_impl_->DrawViewportSize());
  LayerTreeHostImpl::FrameData frame;
  EXPECT_EQ(DRAW_SUCCESS, PrepareToDrawFrame(&frame));
  host_impl_->DrawLayers(&frame);
  host_impl_->DidDrawAllLayers(frame);
  EXPECT_TRUE(host_impl_->SwapBuffers(frame));

  // Ensure the selection bounds have propagated to the frame metadata.
  const ViewportSelection& selection_after =
      fake_output_surface->last_sent_frame().metadata.selection;
  EXPECT_EQ(selection.start.type, selection_after.start.type);
  EXPECT_EQ(selection.end.type, selection_after.end.type);
  EXPECT_EQ(gfx::PointF(selection_bottom), selection_after.start.edge_bottom);
  EXPECT_EQ(gfx::PointF(selection_top), selection_after.start.edge_top);
  EXPECT_TRUE(selection_after.start.visible);
  EXPECT_TRUE(selection_after.start.visible);
}

class SimpleSwapPromiseMonitor : public SwapPromiseMonitor {
 public:
  SimpleSwapPromiseMonitor(LayerTreeHost* layer_tree_host,
                           LayerTreeHostImpl* layer_tree_host_impl,
                           int* set_needs_commit_count,
                           int* set_needs_redraw_count,
                           int* forward_to_main_count)
      : SwapPromiseMonitor(layer_tree_host, layer_tree_host_impl),
        set_needs_commit_count_(set_needs_commit_count),
        set_needs_redraw_count_(set_needs_redraw_count),
        forward_to_main_count_(forward_to_main_count) {}

  ~SimpleSwapPromiseMonitor() override {}

  void OnSetNeedsCommitOnMain() override { (*set_needs_commit_count_)++; }

  void OnSetNeedsRedrawOnImpl() override { (*set_needs_redraw_count_)++; }

  void OnForwardScrollUpdateToMainThreadOnImpl() override {
    (*forward_to_main_count_)++;
  }

 private:
  int* set_needs_commit_count_;
  int* set_needs_redraw_count_;
  int* forward_to_main_count_;
};

TEST_F(LayerTreeHostImplTest, SimpleSwapPromiseMonitor) {
  int set_needs_commit_count = 0;
  int set_needs_redraw_count = 0;
  int forward_to_main_count = 0;

  {
    scoped_ptr<SimpleSwapPromiseMonitor> swap_promise_monitor(
        new SimpleSwapPromiseMonitor(NULL,
                                     host_impl_.get(),
                                     &set_needs_commit_count,
                                     &set_needs_redraw_count,
                                     &forward_to_main_count));
    host_impl_->SetNeedsRedraw();
    EXPECT_EQ(0, set_needs_commit_count);
    EXPECT_EQ(1, set_needs_redraw_count);
    EXPECT_EQ(0, forward_to_main_count);
  }

  // Now the monitor is destroyed, SetNeedsRedraw() is no longer being
  // monitored.
  host_impl_->SetNeedsRedraw();
  EXPECT_EQ(0, set_needs_commit_count);
  EXPECT_EQ(1, set_needs_redraw_count);
  EXPECT_EQ(0, forward_to_main_count);

  {
    scoped_ptr<SimpleSwapPromiseMonitor> swap_promise_monitor(
        new SimpleSwapPromiseMonitor(NULL,
                                     host_impl_.get(),
                                     &set_needs_commit_count,
                                     &set_needs_redraw_count,
                                     &forward_to_main_count));
    host_impl_->SetNeedsRedrawRect(gfx::Rect(10, 10));
    EXPECT_EQ(0, set_needs_commit_count);
    EXPECT_EQ(2, set_needs_redraw_count);
    EXPECT_EQ(0, forward_to_main_count);
  }

  {
    scoped_ptr<SimpleSwapPromiseMonitor> swap_promise_monitor(
        new SimpleSwapPromiseMonitor(NULL,
                                     host_impl_.get(),
                                     &set_needs_commit_count,
                                     &set_needs_redraw_count,
                                     &forward_to_main_count));
    // Empty damage rect won't signal the monitor.
    host_impl_->SetNeedsRedrawRect(gfx::Rect());
    EXPECT_EQ(0, set_needs_commit_count);
    EXPECT_EQ(2, set_needs_redraw_count);
    EXPECT_EQ(0, forward_to_main_count);
  }

  {
    set_needs_commit_count = 0;
    set_needs_redraw_count = 0;
    forward_to_main_count = 0;
    scoped_ptr<SimpleSwapPromiseMonitor> swap_promise_monitor(
        new SimpleSwapPromiseMonitor(NULL,
                                     host_impl_.get(),
                                     &set_needs_commit_count,
                                     &set_needs_redraw_count,
                                     &forward_to_main_count));
    SetupScrollAndContentsLayers(gfx::Size(100, 100));

    // Scrolling normally should not trigger any forwarding.
    EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
              host_impl_
                  ->ScrollBegin(BeginState(gfx::Point()).get(),
                                InputHandler::TOUCHSCREEN)
                  .thread);
    EXPECT_TRUE(
        host_impl_->ScrollBy(
                      UpdateState(gfx::Point(), gfx::Vector2d(0, 10)).get())
            .did_scroll);
    host_impl_->ScrollEnd(EndState().get());

    EXPECT_EQ(0, set_needs_commit_count);
    EXPECT_EQ(1, set_needs_redraw_count);
    EXPECT_EQ(0, forward_to_main_count);

    // Scrolling with a scroll handler should defer the swap to the main
    // thread.
    host_impl_->active_tree()->set_have_scroll_event_handlers(true);
    EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
              host_impl_
                  ->ScrollBegin(BeginState(gfx::Point()).get(),
                                InputHandler::TOUCHSCREEN)
                  .thread);
    EXPECT_TRUE(
        host_impl_->ScrollBy(
                      UpdateState(gfx::Point(), gfx::Vector2d(0, 10)).get())
            .did_scroll);
    host_impl_->ScrollEnd(EndState().get());

    EXPECT_EQ(0, set_needs_commit_count);
    EXPECT_EQ(2, set_needs_redraw_count);
    EXPECT_EQ(1, forward_to_main_count);
  }
}

class LayerTreeHostImplWithTopControlsTest : public LayerTreeHostImplTest {
 public:
  void SetUp() override {
    LayerTreeSettings settings = DefaultSettings();
    CreateHostImpl(settings, CreateOutputSurface());
    host_impl_->active_tree()->set_top_controls_height(top_controls_height_);
    host_impl_->sync_tree()->set_top_controls_height(top_controls_height_);
    host_impl_->active_tree()->SetCurrentTopControlsShownRatio(1.f);
  }

 protected:
  static const int top_controls_height_;
};

const int LayerTreeHostImplWithTopControlsTest::top_controls_height_ = 50;

TEST_F(LayerTreeHostImplWithTopControlsTest, NoIdleAnimations) {
  LayerImpl* scroll_layer = SetupScrollAndContentsLayers(gfx::Size(100, 100));
  scroll_layer->layer_tree_impl()
      ->property_trees()
      ->scroll_tree.UpdateScrollOffsetBaseForTesting(scroll_layer->id(),
                                                     gfx::ScrollOffset(0, 10));
  BeginFrameArgs begin_frame_args =
      CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE);
  host_impl_->WillBeginImplFrame(begin_frame_args);
  host_impl_->Animate();
  EXPECT_FALSE(did_request_redraw_);
  host_impl_->DidFinishImplFrame();
}

TEST_F(LayerTreeHostImplWithTopControlsTest, TopControlsHeightIsCommitted) {
  SetupScrollAndContentsLayers(gfx::Size(100, 100));
  EXPECT_FALSE(did_request_redraw_);
  host_impl_->CreatePendingTree();
  host_impl_->sync_tree()->set_top_controls_height(100);
  host_impl_->ActivateSyncTree();
  EXPECT_EQ(100, host_impl_->top_controls_manager()->TopControlsHeight());
}

TEST_F(LayerTreeHostImplWithTopControlsTest,
       TopControlsStayFullyVisibleOnHeightChange) {
  SetupScrollAndContentsLayers(gfx::Size(100, 100));
  EXPECT_EQ(0.f, host_impl_->top_controls_manager()->ControlsTopOffset());

  host_impl_->CreatePendingTree();
  host_impl_->sync_tree()->set_top_controls_height(0);
  host_impl_->ActivateSyncTree();
  EXPECT_EQ(0.f, host_impl_->top_controls_manager()->ControlsTopOffset());

  host_impl_->CreatePendingTree();
  host_impl_->sync_tree()->set_top_controls_height(50);
  host_impl_->ActivateSyncTree();
  EXPECT_EQ(0.f, host_impl_->top_controls_manager()->ControlsTopOffset());
}

TEST_F(LayerTreeHostImplWithTopControlsTest, TopControlsAnimationScheduling) {
  LayerImpl* scroll_layer = SetupScrollAndContentsLayers(gfx::Size(100, 100));
  scroll_layer->layer_tree_impl()
      ->property_trees()
      ->scroll_tree.UpdateScrollOffsetBaseForTesting(scroll_layer->id(),
                                                     gfx::ScrollOffset(0, 10));
  host_impl_->DidChangeTopControlsPosition();
  EXPECT_TRUE(did_request_next_frame_);
  EXPECT_TRUE(did_request_redraw_);
}

TEST_F(LayerTreeHostImplWithTopControlsTest, ScrollHandledByTopControls) {
  InputHandlerScrollResult result;
  LayerImpl* scroll_layer = SetupScrollAndContentsLayers(gfx::Size(100, 200));
  host_impl_->SetViewportSize(gfx::Size(100, 100));
  host_impl_->top_controls_manager()->UpdateTopControlsState(
      BOTH, SHOWN, false);
  DrawFrame();

  EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
            host_impl_
                ->ScrollBegin(BeginState(gfx::Point()).get(),
                              InputHandler::TOUCHSCREEN)
                .thread);
  EXPECT_EQ(0, host_impl_->top_controls_manager()->ControlsTopOffset());
  EXPECT_EQ(gfx::Vector2dF().ToString(),
            scroll_layer->CurrentScrollOffset().ToString());

  // Scroll just the top controls and verify that the scroll succeeds.
  const float residue = 10;
  float offset = top_controls_height_ - residue;
  result = host_impl_->ScrollBy(
      UpdateState(gfx::Point(), gfx::Vector2d(0, offset)).get());
  EXPECT_EQ(result.unused_scroll_delta, gfx::Vector2d(0, 0));
  EXPECT_TRUE(result.did_scroll);
  EXPECT_FLOAT_EQ(-offset,
                  host_impl_->top_controls_manager()->ControlsTopOffset());
  EXPECT_EQ(gfx::Vector2dF().ToString(),
            scroll_layer->CurrentScrollOffset().ToString());

  // Scroll across the boundary
  const float content_scroll = 20;
  offset = residue + content_scroll;
  result = host_impl_->ScrollBy(
      UpdateState(gfx::Point(), gfx::Vector2d(0, offset)).get());
  EXPECT_TRUE(result.did_scroll);
  EXPECT_EQ(result.unused_scroll_delta, gfx::Vector2d(0, 0));
  EXPECT_EQ(-top_controls_height_,
            host_impl_->top_controls_manager()->ControlsTopOffset());
  EXPECT_EQ(gfx::Vector2dF(0, content_scroll).ToString(),
            scroll_layer->CurrentScrollOffset().ToString());

  // Now scroll back to the top of the content
  offset = -content_scroll;
  result = host_impl_->ScrollBy(
      UpdateState(gfx::Point(), gfx::Vector2d(0, offset)).get());
  EXPECT_TRUE(result.did_scroll);
  EXPECT_EQ(result.unused_scroll_delta, gfx::Vector2d(0, 0));
  EXPECT_EQ(-top_controls_height_,
            host_impl_->top_controls_manager()->ControlsTopOffset());
  EXPECT_EQ(gfx::Vector2dF().ToString(),
            scroll_layer->CurrentScrollOffset().ToString());

  // And scroll the top controls completely into view
  offset = -top_controls_height_;
  result = host_impl_->ScrollBy(
      UpdateState(gfx::Point(), gfx::Vector2d(0, offset)).get());
  EXPECT_TRUE(result.did_scroll);
  EXPECT_EQ(result.unused_scroll_delta, gfx::Vector2d(0, 0));
  EXPECT_EQ(0, host_impl_->top_controls_manager()->ControlsTopOffset());
  EXPECT_EQ(gfx::Vector2dF().ToString(),
            scroll_layer->CurrentScrollOffset().ToString());

  // And attempt to scroll past the end
  result = host_impl_->ScrollBy(
      UpdateState(gfx::Point(), gfx::Vector2d(0, offset)).get());
  EXPECT_FALSE(result.did_scroll);
  EXPECT_EQ(result.unused_scroll_delta, gfx::Vector2d(0, -50));
  EXPECT_EQ(0, host_impl_->top_controls_manager()->ControlsTopOffset());
  EXPECT_EQ(gfx::Vector2dF().ToString(),
            scroll_layer->CurrentScrollOffset().ToString());

  host_impl_->ScrollEnd(EndState().get());
}

TEST_F(LayerTreeHostImplWithTopControlsTest, WheelUnhandledByTopControls) {
  SetupScrollAndContentsLayers(gfx::Size(100, 200));
  host_impl_->SetViewportSize(gfx::Size(50, 100));
  host_impl_->active_tree()->set_top_controls_shrink_blink_size(true);
  host_impl_->top_controls_manager()->UpdateTopControlsState(BOTH, SHOWN,
                                                             false);
  DrawFrame();

  LayerImpl* viewport_layer = host_impl_->InnerViewportScrollLayer();

  EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
            host_impl_->ScrollBegin(BeginState(gfx::Point()).get(),
                                    InputHandler::WHEEL)
                .thread);
  EXPECT_EQ(0, host_impl_->top_controls_manager()->ControlsTopOffset());
  EXPECT_VECTOR_EQ(gfx::Vector2dF(), viewport_layer->CurrentScrollOffset());

  // Wheel scrolls should not affect the top controls, and should pass
  // directly through to the viewport.
  const float delta = top_controls_height_;
  EXPECT_TRUE(
      host_impl_->ScrollBy(
                    UpdateState(gfx::Point(), gfx::Vector2d(0, delta)).get())
          .did_scroll);
  EXPECT_FLOAT_EQ(0, host_impl_->top_controls_manager()->ControlsTopOffset());
  EXPECT_VECTOR_EQ(gfx::Vector2dF(0, delta),
                   viewport_layer->CurrentScrollOffset());

  EXPECT_TRUE(
      host_impl_->ScrollBy(
                    UpdateState(gfx::Point(), gfx::Vector2d(0, delta)).get())
          .did_scroll);
  EXPECT_FLOAT_EQ(0, host_impl_->top_controls_manager()->ControlsTopOffset());
  EXPECT_VECTOR_EQ(gfx::Vector2dF(0, delta * 2),
                   viewport_layer->CurrentScrollOffset());
}

TEST_F(LayerTreeHostImplWithTopControlsTest, TopControlsAnimationAtOrigin) {
  LayerImpl* scroll_layer = SetupScrollAndContentsLayers(gfx::Size(100, 200));
  host_impl_->SetViewportSize(gfx::Size(100, 200));
  host_impl_->top_controls_manager()->UpdateTopControlsState(
      BOTH, SHOWN, false);
  DrawFrame();

  EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
            host_impl_
                ->ScrollBegin(BeginState(gfx::Point()).get(),
                              InputHandler::TOUCHSCREEN)
                .thread);
  EXPECT_EQ(0, host_impl_->top_controls_manager()->ControlsTopOffset());
  EXPECT_EQ(gfx::Vector2dF().ToString(),
            scroll_layer->CurrentScrollOffset().ToString());

  // Scroll the top controls partially.
  const float residue = 35;
  float offset = top_controls_height_ - residue;
  EXPECT_TRUE(
      host_impl_->ScrollBy(
                    UpdateState(gfx::Point(), gfx::Vector2d(0, offset)).get())
          .did_scroll);
  EXPECT_FLOAT_EQ(-offset,
                  host_impl_->top_controls_manager()->ControlsTopOffset());
  EXPECT_EQ(gfx::Vector2dF().ToString(),
            scroll_layer->CurrentScrollOffset().ToString());

  did_request_redraw_ = false;
  did_request_next_frame_ = false;
  did_request_commit_ = false;

  // End the scroll while the controls are still offset from their limit.
  host_impl_->ScrollEnd(EndState().get());
  ASSERT_TRUE(host_impl_->top_controls_manager()->has_animation());
  EXPECT_TRUE(did_request_next_frame_);
  EXPECT_TRUE(did_request_redraw_);
  EXPECT_FALSE(did_request_commit_);

  // The top controls should properly animate until finished, despite the scroll
  // offset being at the origin.
  BeginFrameArgs begin_frame_args = CreateBeginFrameArgsForTesting(
      BEGINFRAME_FROM_HERE, base::TimeTicks::Now());
  while (did_request_next_frame_) {
    did_request_redraw_ = false;
    did_request_next_frame_ = false;
    did_request_commit_ = false;

    float old_offset =
        host_impl_->top_controls_manager()->ControlsTopOffset();

    begin_frame_args.frame_time += base::TimeDelta::FromMilliseconds(5);
    host_impl_->WillBeginImplFrame(begin_frame_args);
    host_impl_->Animate();
    EXPECT_EQ(gfx::Vector2dF().ToString(),
              scroll_layer->CurrentScrollOffset().ToString());

    float new_offset =
        host_impl_->top_controls_manager()->ControlsTopOffset();

    // No commit is needed as the controls are animating the content offset,
    // not the scroll offset.
    EXPECT_FALSE(did_request_commit_);

    if (new_offset != old_offset)
      EXPECT_TRUE(did_request_redraw_);

    if (new_offset != 0) {
      EXPECT_TRUE(host_impl_->top_controls_manager()->has_animation());
      EXPECT_TRUE(did_request_next_frame_);
    }
    host_impl_->DidFinishImplFrame();
  }
  EXPECT_FALSE(host_impl_->top_controls_manager()->has_animation());
}

TEST_F(LayerTreeHostImplWithTopControlsTest, TopControlsAnimationAfterScroll) {
  LayerImpl* scroll_layer = SetupScrollAndContentsLayers(gfx::Size(100, 200));
  host_impl_->SetViewportSize(gfx::Size(100, 100));
  host_impl_->top_controls_manager()->UpdateTopControlsState(
      BOTH, SHOWN, false);
  float initial_scroll_offset = 50;
  scroll_layer->layer_tree_impl()
      ->property_trees()
      ->scroll_tree.UpdateScrollOffsetBaseForTesting(
          scroll_layer->id(), gfx::ScrollOffset(0, initial_scroll_offset));
  DrawFrame();

  EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
            host_impl_
                ->ScrollBegin(BeginState(gfx::Point()).get(),
                              InputHandler::TOUCHSCREEN)
                .thread);
  EXPECT_EQ(0, host_impl_->top_controls_manager()->ControlsTopOffset());
  EXPECT_EQ(gfx::Vector2dF(0, initial_scroll_offset).ToString(),
            scroll_layer->CurrentScrollOffset().ToString());

  // Scroll the top controls partially.
  const float residue = 15;
  float offset = top_controls_height_ - residue;
  EXPECT_TRUE(
      host_impl_->ScrollBy(
                    UpdateState(gfx::Point(), gfx::Vector2d(0, offset)).get())
          .did_scroll);
  EXPECT_FLOAT_EQ(-offset,
                  host_impl_->top_controls_manager()->ControlsTopOffset());
  EXPECT_EQ(gfx::Vector2dF(0, initial_scroll_offset).ToString(),
            scroll_layer->CurrentScrollOffset().ToString());

  did_request_redraw_ = false;
  did_request_next_frame_ = false;
  did_request_commit_ = false;

  // End the scroll while the controls are still offset from the limit.
  host_impl_->ScrollEnd(EndState().get());
  ASSERT_TRUE(host_impl_->top_controls_manager()->has_animation());
  EXPECT_TRUE(did_request_next_frame_);
  EXPECT_TRUE(did_request_redraw_);
  EXPECT_FALSE(did_request_commit_);

  // Animate the top controls to the limit.
  BeginFrameArgs begin_frame_args = CreateBeginFrameArgsForTesting(
      BEGINFRAME_FROM_HERE, base::TimeTicks::Now());
  while (did_request_next_frame_) {
    did_request_redraw_ = false;
    did_request_next_frame_ = false;
    did_request_commit_ = false;

    float old_offset =
        host_impl_->top_controls_manager()->ControlsTopOffset();

    begin_frame_args.frame_time += base::TimeDelta::FromMilliseconds(5);
    host_impl_->WillBeginImplFrame(begin_frame_args);
    host_impl_->Animate();

    float new_offset =
        host_impl_->top_controls_manager()->ControlsTopOffset();

    if (new_offset != old_offset) {
      EXPECT_TRUE(did_request_redraw_);
      EXPECT_TRUE(did_request_commit_);
    }
    host_impl_->DidFinishImplFrame();
  }
  EXPECT_FALSE(host_impl_->top_controls_manager()->has_animation());
  EXPECT_EQ(-top_controls_height_,
            host_impl_->top_controls_manager()->ControlsTopOffset());
}

TEST_F(LayerTreeHostImplWithTopControlsTest,
       TopControlsAnimationAfterMainThreadFlingStopped) {
  LayerImpl* scroll_layer = SetupScrollAndContentsLayers(gfx::Size(100, 200));
  host_impl_->SetViewportSize(gfx::Size(100, 100));
  host_impl_->top_controls_manager()->UpdateTopControlsState(BOTH, SHOWN,
                                                             false);
  float initial_scroll_offset = 50;
  scroll_layer->layer_tree_impl()
      ->property_trees()
      ->scroll_tree.UpdateScrollOffsetBaseForTesting(
          scroll_layer->id(), gfx::ScrollOffset(0, initial_scroll_offset));
  DrawFrame();

  EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
            host_impl_
                ->ScrollBegin(BeginState(gfx::Point()).get(),
                              InputHandler::TOUCHSCREEN)
                .thread);
  EXPECT_EQ(0, host_impl_->top_controls_manager()->ControlsTopOffset());
  EXPECT_EQ(gfx::Vector2dF(0, initial_scroll_offset).ToString(),
            scroll_layer->CurrentScrollOffset().ToString());

  // Scroll the top controls partially.
  const float residue = 15;
  float offset = top_controls_height_ - residue;
  EXPECT_TRUE(
      host_impl_->ScrollBy(
                    UpdateState(gfx::Point(), gfx::Vector2d(0, offset)).get())
          .did_scroll);
  EXPECT_FLOAT_EQ(-offset,
                  host_impl_->top_controls_manager()->ControlsTopOffset());
  EXPECT_EQ(gfx::Vector2dF(0, initial_scroll_offset).ToString(),
            scroll_layer->CurrentScrollOffset().ToString());

  did_request_redraw_ = false;
  did_request_next_frame_ = false;
  did_request_commit_ = false;

  // End the fling while the controls are still offset from the limit.
  host_impl_->MainThreadHasStoppedFlinging();
  ASSERT_TRUE(host_impl_->top_controls_manager()->has_animation());
  EXPECT_TRUE(did_request_next_frame_);
  EXPECT_TRUE(did_request_redraw_);
  EXPECT_FALSE(did_request_commit_);

  // Animate the top controls to the limit.
  BeginFrameArgs begin_frame_args = CreateBeginFrameArgsForTesting(
      BEGINFRAME_FROM_HERE, base::TimeTicks::Now());
  while (did_request_next_frame_) {
    did_request_redraw_ = false;
    did_request_next_frame_ = false;
    did_request_commit_ = false;

    float old_offset = host_impl_->top_controls_manager()->ControlsTopOffset();

    begin_frame_args.frame_time += base::TimeDelta::FromMilliseconds(5);
    host_impl_->WillBeginImplFrame(begin_frame_args);
    host_impl_->Animate();

    float new_offset = host_impl_->top_controls_manager()->ControlsTopOffset();

    if (new_offset != old_offset) {
      EXPECT_TRUE(did_request_redraw_);
      EXPECT_TRUE(did_request_commit_);
    }
    host_impl_->DidFinishImplFrame();
  }
  EXPECT_FALSE(host_impl_->top_controls_manager()->has_animation());
  EXPECT_EQ(-top_controls_height_,
            host_impl_->top_controls_manager()->ControlsTopOffset());
}

TEST_F(LayerTreeHostImplWithTopControlsTest,
       TopControlsScrollDeltaInOverScroll) {
  // Verifies that the overscroll delta should not have accumulated in
  // the top controls if we do a hide and show without releasing finger.

  LayerImpl* scroll_layer = SetupScrollAndContentsLayers(gfx::Size(100, 200));
  host_impl_->SetViewportSize(gfx::Size(100, 100));
  host_impl_->top_controls_manager()->UpdateTopControlsState(BOTH, SHOWN,
                                                             false);
  DrawFrame();

  EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
            host_impl_
                ->ScrollBegin(BeginState(gfx::Point()).get(),
                              InputHandler::TOUCHSCREEN)
                .thread);
  EXPECT_EQ(0, host_impl_->top_controls_manager()->ControlsTopOffset());

  float offset = 50;
  EXPECT_TRUE(
      host_impl_->ScrollBy(
                    UpdateState(gfx::Point(), gfx::Vector2d(0, offset)).get())
          .did_scroll);
  EXPECT_EQ(-offset, host_impl_->top_controls_manager()->ControlsTopOffset());
  EXPECT_EQ(gfx::Vector2dF().ToString(),
            scroll_layer->CurrentScrollOffset().ToString());

  EXPECT_TRUE(
      host_impl_->ScrollBy(
                    UpdateState(gfx::Point(), gfx::Vector2d(0, offset)).get())
          .did_scroll);
  EXPECT_EQ(gfx::Vector2dF(0, offset).ToString(),
            scroll_layer->CurrentScrollOffset().ToString());

  EXPECT_TRUE(
      host_impl_->ScrollBy(
                    UpdateState(gfx::Point(), gfx::Vector2d(0, offset)).get())
          .did_scroll);

  // Should have fully scrolled
  EXPECT_EQ(gfx::Vector2dF(0, scroll_layer->MaxScrollOffset().y()).ToString(),
            scroll_layer->CurrentScrollOffset().ToString());

  float overscrollamount = 10;

  // Overscroll the content
  EXPECT_FALSE(
      host_impl_->ScrollBy(UpdateState(gfx::Point(),
                                       gfx::Vector2d(0, overscrollamount))
                               .get())
          .did_scroll);
  EXPECT_EQ(gfx::Vector2dF(0, 2 * offset).ToString(),
            scroll_layer->CurrentScrollOffset().ToString());
  EXPECT_EQ(gfx::Vector2dF(0, overscrollamount).ToString(),
            host_impl_->accumulated_root_overscroll().ToString());

  EXPECT_TRUE(host_impl_->ScrollBy(UpdateState(gfx::Point(),
                                               gfx::Vector2d(0, -2 * offset))
                                       .get())
                  .did_scroll);
  EXPECT_EQ(gfx::Vector2dF(0, 0).ToString(),
            scroll_layer->CurrentScrollOffset().ToString());
  EXPECT_EQ(-offset, host_impl_->top_controls_manager()->ControlsTopOffset());

  EXPECT_TRUE(
      host_impl_->ScrollBy(
                    UpdateState(gfx::Point(), gfx::Vector2d(0, -offset)).get())
          .did_scroll);
  EXPECT_EQ(gfx::Vector2dF(0, 0).ToString(),
            scroll_layer->CurrentScrollOffset().ToString());

  // Top controls should be fully visible
  EXPECT_EQ(0, host_impl_->top_controls_manager()->ControlsTopOffset());

  host_impl_->ScrollEnd(EndState().get());
}

class LayerTreeHostImplVirtualViewportTest : public LayerTreeHostImplTest {
 public:
  void SetupVirtualViewportLayers(const gfx::Size& content_size,
                                  const gfx::Size& outer_viewport,
                                  const gfx::Size& inner_viewport) {
    LayerTreeImpl* layer_tree_impl = host_impl_->active_tree();
    const int kOuterViewportClipLayerId = 6;
    const int kOuterViewportScrollLayerId = 7;
    const int kInnerViewportScrollLayerId = 2;
    const int kInnerViewportClipLayerId = 4;
    const int kPageScaleLayerId = 5;

    scoped_ptr<LayerImpl> inner_scroll =
        LayerImpl::Create(layer_tree_impl, kInnerViewportScrollLayerId);
    inner_scroll->SetIsContainerForFixedPositionLayers(true);
    inner_scroll->layer_tree_impl()
        ->property_trees()
        ->scroll_tree.UpdateScrollOffsetBaseForTesting(inner_scroll->id(),
                                                       gfx::ScrollOffset());

    scoped_ptr<LayerImpl> inner_clip =
        LayerImpl::Create(layer_tree_impl, kInnerViewportClipLayerId);
    inner_clip->SetBounds(inner_viewport);

    scoped_ptr<LayerImpl> page_scale =
        LayerImpl::Create(layer_tree_impl, kPageScaleLayerId);

    inner_scroll->SetScrollClipLayer(inner_clip->id());
    inner_scroll->SetBounds(outer_viewport);
    inner_scroll->SetPosition(gfx::PointF());

    scoped_ptr<LayerImpl> outer_clip =
        LayerImpl::Create(layer_tree_impl, kOuterViewportClipLayerId);
    outer_clip->SetBounds(outer_viewport);
    outer_clip->SetIsContainerForFixedPositionLayers(true);

    scoped_ptr<LayerImpl> outer_scroll =
        LayerImpl::Create(layer_tree_impl, kOuterViewportScrollLayerId);
    outer_scroll->SetScrollClipLayer(outer_clip->id());
    outer_scroll->layer_tree_impl()
        ->property_trees()
        ->scroll_tree.UpdateScrollOffsetBaseForTesting(outer_scroll->id(),
                                                       gfx::ScrollOffset());
    outer_scroll->SetBounds(content_size);
    outer_scroll->SetPosition(gfx::PointF());

    scoped_ptr<LayerImpl> contents =
        LayerImpl::Create(layer_tree_impl, 8);
    contents->SetDrawsContent(true);
    contents->SetBounds(content_size);
    contents->SetPosition(gfx::PointF());

    outer_scroll->AddChild(std::move(contents));
    outer_clip->AddChild(std::move(outer_scroll));
    inner_scroll->AddChild(std::move(outer_clip));
    page_scale->AddChild(std::move(inner_scroll));
    inner_clip->AddChild(std::move(page_scale));

    inner_clip->SetForceRenderSurface(true);
    layer_tree_impl->SetRootLayer(std::move(inner_clip));
    layer_tree_impl->SetViewportLayersFromIds(
        Layer::INVALID_ID, kPageScaleLayerId, kInnerViewportScrollLayerId,
        kOuterViewportScrollLayerId);

    host_impl_->active_tree()->DidBecomeActive();
  }
};

TEST_F(LayerTreeHostImplVirtualViewportTest, ScrollBothInnerAndOuterLayer) {
  gfx::Size content_size = gfx::Size(100, 160);
  gfx::Size outer_viewport = gfx::Size(50, 80);
  gfx::Size inner_viewport = gfx::Size(25, 40);

  SetupVirtualViewportLayers(content_size, outer_viewport, inner_viewport);

  LayerImpl* outer_scroll = host_impl_->OuterViewportScrollLayer();
  LayerImpl* inner_scroll = host_impl_->InnerViewportScrollLayer();
  SetNeedsRebuildPropertyTrees();
  DrawFrame();
  {
    gfx::ScrollOffset inner_expected;
    gfx::ScrollOffset outer_expected;
    EXPECT_EQ(inner_expected, inner_scroll->CurrentScrollOffset());
    EXPECT_EQ(outer_expected, outer_scroll->CurrentScrollOffset());

    gfx::ScrollOffset current_offset(70.f, 100.f);

    host_impl_->SetSynchronousInputHandlerRootScrollOffset(current_offset);
    EXPECT_EQ(gfx::ScrollOffset(25.f, 40.f), inner_scroll->MaxScrollOffset());
    EXPECT_EQ(gfx::ScrollOffset(50.f, 80.f), outer_scroll->MaxScrollOffset());

    // Outer viewport scrolls first. Then the rest is applied to the inner
    // viewport.
    EXPECT_EQ(gfx::ScrollOffset(20.f, 20.f),
              inner_scroll->CurrentScrollOffset());
    EXPECT_EQ(gfx::ScrollOffset(50.f, 80.f),
              outer_scroll->CurrentScrollOffset());
  }
}

TEST_F(LayerTreeHostImplVirtualViewportTest, FlingScrollBubblesToInner) {
  gfx::Size content_size = gfx::Size(200, 320);
  gfx::Size outer_viewport = gfx::Size(100, 160);
  gfx::Size inner_viewport = gfx::Size(50, 80);

  SetupVirtualViewportLayers(content_size, outer_viewport, inner_viewport);

  LayerImpl* outer_scroll = host_impl_->OuterViewportScrollLayer();
  LayerImpl* inner_scroll = host_impl_->InnerViewportScrollLayer();
  SetNeedsRebuildPropertyTrees();
  DrawFrame();
  {
    gfx::Vector2dF inner_expected;
    gfx::Vector2dF outer_expected;
    EXPECT_VECTOR_EQ(inner_expected, inner_scroll->CurrentScrollOffset());
    EXPECT_VECTOR_EQ(outer_expected, outer_scroll->CurrentScrollOffset());

    // Scrolling the viewport always sets the outer scroll layer as the
    // currently scrolling layer.
    EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
              host_impl_
                  ->ScrollBegin(BeginState(gfx::Point()).get(),
                                InputHandler::TOUCHSCREEN)
                  .thread);
    EXPECT_EQ(inner_scroll, host_impl_->CurrentlyScrollingLayer());
    EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
              host_impl_->FlingScrollBegin().thread);
    EXPECT_EQ(inner_scroll, host_impl_->CurrentlyScrollingLayer());

    gfx::Vector2d scroll_delta(inner_viewport.width() / 2.f,
                               inner_viewport.height() / 2.f);
    host_impl_->ScrollBy(UpdateState(gfx::Point(), scroll_delta).get());
    inner_expected += gfx::Vector2dF(scroll_delta.x(), scroll_delta.y());
    EXPECT_EQ(inner_scroll, host_impl_->CurrentlyScrollingLayer());

    host_impl_->ScrollEnd(EndState().get());
    EXPECT_EQ(nullptr, host_impl_->CurrentlyScrollingLayer());

    EXPECT_VECTOR_EQ(inner_expected, inner_scroll->CurrentScrollOffset());
    EXPECT_VECTOR_EQ(outer_expected, outer_scroll->CurrentScrollOffset());

    // Fling past the inner viewport boundry, make sure outer viewport scrolls.
    EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
              host_impl_
                  ->ScrollBegin(BeginState(gfx::Point()).get(),
                                InputHandler::TOUCHSCREEN)
                  .thread);
    EXPECT_EQ(inner_scroll, host_impl_->CurrentlyScrollingLayer());
    EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
              host_impl_->FlingScrollBegin().thread);
    EXPECT_EQ(inner_scroll, host_impl_->CurrentlyScrollingLayer());

    host_impl_->ScrollBy(UpdateState(gfx::Point(), scroll_delta).get());
    inner_expected += gfx::Vector2dF(scroll_delta.x(), scroll_delta.y());
    EXPECT_EQ(inner_scroll, host_impl_->CurrentlyScrollingLayer());

    host_impl_->ScrollBy(UpdateState(gfx::Point(), scroll_delta).get());
    outer_expected += gfx::Vector2dF(scroll_delta.x(), scroll_delta.y());
    EXPECT_EQ(inner_scroll, host_impl_->CurrentlyScrollingLayer());

    host_impl_->ScrollEnd(EndState().get());
    EXPECT_EQ(nullptr, host_impl_->CurrentlyScrollingLayer());

    EXPECT_VECTOR_EQ(inner_expected, inner_scroll->CurrentScrollOffset());
    EXPECT_VECTOR_EQ(outer_expected, outer_scroll->CurrentScrollOffset());
  }
}

TEST_F(LayerTreeHostImplVirtualViewportTest,
       DiagonalScrollBubblesPerfectlyToInner) {
  gfx::Size content_size = gfx::Size(200, 320);
  gfx::Size outer_viewport = gfx::Size(100, 160);
  gfx::Size inner_viewport = gfx::Size(50, 80);

  SetupVirtualViewportLayers(content_size, outer_viewport, inner_viewport);

  LayerImpl* outer_scroll = host_impl_->OuterViewportScrollLayer();
  LayerImpl* inner_scroll = host_impl_->InnerViewportScrollLayer();
  SetNeedsRebuildPropertyTrees();
  DrawFrame();
  {
    gfx::Vector2dF inner_expected;
    gfx::Vector2dF outer_expected;
    EXPECT_VECTOR_EQ(inner_expected, inner_scroll->CurrentScrollOffset());
    EXPECT_VECTOR_EQ(outer_expected, outer_scroll->CurrentScrollOffset());

    // Make sure the scroll goes to the inner viewport first.
    EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
              host_impl_
                  ->ScrollBegin(BeginState(gfx::Point()).get(),
                                InputHandler::TOUCHSCREEN)
                  .thread);
    EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
              host_impl_->FlingScrollBegin().thread);
    EXPECT_TRUE(host_impl_->IsCurrentlyScrollingLayerAt(
        gfx::Point(), InputHandler::TOUCHSCREEN));

    // Scroll near the edge of the outer viewport.
    gfx::Vector2d scroll_delta(inner_viewport.width() / 2.f,
                               inner_viewport.height() / 2.f);
    host_impl_->ScrollBy(UpdateState(gfx::Point(), scroll_delta).get());
    inner_expected += scroll_delta;
    EXPECT_TRUE(host_impl_->IsCurrentlyScrollingLayerAt(
        gfx::Point(), InputHandler::TOUCHSCREEN));

    EXPECT_VECTOR_EQ(inner_expected, inner_scroll->CurrentScrollOffset());
    EXPECT_VECTOR_EQ(outer_expected, outer_scroll->CurrentScrollOffset());

    // Now diagonal scroll across the outer viewport boundary in a single event.
    // The entirety of the scroll should be consumed, as bubbling between inner
    // and outer viewport layers is perfect.
    host_impl_->ScrollBy(
        UpdateState(gfx::Point(), gfx::ScaleVector2d(scroll_delta, 2)).get());
    EXPECT_TRUE(host_impl_->IsCurrentlyScrollingLayerAt(
        gfx::Point(), InputHandler::TOUCHSCREEN));
    outer_expected += scroll_delta;
    inner_expected += scroll_delta;
    host_impl_->ScrollEnd(EndState().get());
    EXPECT_FALSE(host_impl_->IsCurrentlyScrollingLayerAt(
        gfx::Point(), InputHandler::TOUCHSCREEN));

    EXPECT_VECTOR_EQ(inner_expected, inner_scroll->CurrentScrollOffset());
    EXPECT_VECTOR_EQ(outer_expected, outer_scroll->CurrentScrollOffset());
  }
}

TEST_F(LayerTreeHostImplVirtualViewportTest,
       TouchFlingDoesntSwitchScrollingLayer) {
  gfx::Size content_size = gfx::Size(100, 160);
  gfx::Size outer_viewport = gfx::Size(50, 80);
  gfx::Size inner_viewport = gfx::Size(25, 40);

  SetupVirtualViewportLayers(content_size, outer_viewport, inner_viewport);

  LayerImpl* outer_scroll = host_impl_->OuterViewportScrollLayer();
  LayerImpl* inner_scroll = host_impl_->InnerViewportScrollLayer();

  scoped_ptr<LayerImpl> child =
      CreateScrollableLayer(10, outer_viewport, outer_scroll);
  LayerImpl* child_scroll = child.get();
  outer_scroll->children()[0]->AddChild(std::move(child));

  SetNeedsRebuildPropertyTrees();
  DrawFrame();
  {
    scoped_ptr<ScrollAndScaleSet> scroll_info;

    gfx::Vector2d scroll_delta(0, inner_viewport.height());
    EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
              host_impl_
                  ->ScrollBegin(BeginState(gfx::Point()).get(),
                                InputHandler::TOUCHSCREEN)
                  .thread);
    EXPECT_TRUE(
        host_impl_->ScrollBy(UpdateState(gfx::Point(), scroll_delta).get())
            .did_scroll);
    EXPECT_TRUE(host_impl_->IsCurrentlyScrollingLayerAt(
        gfx::Point(), InputHandler::TOUCHSCREEN));

    // The child should have scrolled up to its limit.
    scroll_info = host_impl_->ProcessScrollDeltas();
    ASSERT_EQ(1u, scroll_info->scrolls.size());
    EXPECT_TRUE(
        ScrollInfoContains(*scroll_info, child_scroll->id(), scroll_delta));
    EXPECT_EQ(host_impl_->CurrentlyScrollingLayer(), child_scroll);

    // The fling have no effect on the currently scrolling layer.
    EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
              host_impl_->FlingScrollBegin().thread);
    EXPECT_FALSE(
        host_impl_->ScrollBy(UpdateState(gfx::Point(), scroll_delta).get())
            .did_scroll);
    EXPECT_EQ(host_impl_->CurrentlyScrollingLayer(), child_scroll);
    EXPECT_TRUE(host_impl_->IsCurrentlyScrollingLayerAt(
        gfx::Point(), InputHandler::TOUCHSCREEN));

    // The inner viewport shouldn't have scrolled.
    scroll_info = host_impl_->ProcessScrollDeltas();
    ASSERT_EQ(1u, scroll_info->scrolls.size());
    EXPECT_TRUE(
        ScrollInfoContains(*scroll_info, child_scroll->id(), scroll_delta));
    ExpectNone(*scroll_info, inner_scroll->id());

    // As the locked layer is at its limit, no further scrolling can occur.
    EXPECT_FALSE(
        host_impl_->ScrollBy(UpdateState(gfx::Point(), scroll_delta).get())
            .did_scroll);
    EXPECT_EQ(host_impl_->CurrentlyScrollingLayer(), child_scroll);
    host_impl_->ScrollEnd(EndState().get());
    EXPECT_FALSE(host_impl_->IsCurrentlyScrollingLayerAt(
        gfx::Point(), InputHandler::TOUCHSCREEN));
  }
}

TEST_F(LayerTreeHostImplVirtualViewportTest,
       ScrollBeginEventThatTargetsViewportLayerSkipsHitTest) {
  gfx::Size content_size = gfx::Size(100, 160);
  gfx::Size outer_viewport = gfx::Size(50, 80);
  gfx::Size inner_viewport = gfx::Size(25, 40);

  SetupVirtualViewportLayers(content_size, outer_viewport, inner_viewport);

  LayerImpl* outer_scroll = host_impl_->OuterViewportScrollLayer();
  LayerImpl* inner_scroll = host_impl_->InnerViewportScrollLayer();

  scoped_ptr<LayerImpl> child =
      CreateScrollableLayer(10, outer_viewport, outer_scroll);
  LayerImpl* child_scroll = child.get();
  outer_scroll->children()[0]->AddChild(std::move(child));

  SetNeedsRebuildPropertyTrees();
  DrawFrame();

  EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
            host_impl_
                ->RootScrollBegin(BeginState(gfx::Point()).get(),
                                  InputHandler::TOUCHSCREEN)
                .thread);
  EXPECT_EQ(host_impl_->CurrentlyScrollingLayer(), inner_scroll);
  host_impl_->ScrollEnd(EndState().get());
  EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
            host_impl_
                ->ScrollBegin(BeginState(gfx::Point()).get(),
                              InputHandler::TOUCHSCREEN)
                .thread);
  EXPECT_EQ(host_impl_->CurrentlyScrollingLayer(), child_scroll);
  host_impl_->ScrollEnd(EndState().get());
}

TEST_F(LayerTreeHostImplVirtualViewportTest,
       NoOverscrollWhenInnerViewportCantScroll) {
  InputHandlerScrollResult scroll_result;
  gfx::Size content_size = gfx::Size(100, 160);
  gfx::Size outer_viewport = gfx::Size(50, 80);
  gfx::Size inner_viewport = gfx::Size(25, 40);
  SetupVirtualViewportLayers(content_size, outer_viewport, inner_viewport);
  // Make inner viewport unscrollable.
  LayerImpl* inner_scroll = host_impl_->InnerViewportScrollLayer();
  inner_scroll->set_user_scrollable_horizontal(false);
  inner_scroll->set_user_scrollable_vertical(false);
  SetNeedsRebuildPropertyTrees();
  DrawFrame();

  // Ensure inner viewport doesn't react to scrolls (test it's unscrollable).
  EXPECT_VECTOR_EQ(gfx::Vector2dF(), inner_scroll->CurrentScrollOffset());
  EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
            host_impl_
                ->ScrollBegin(BeginState(gfx::Point()).get(),
                              InputHandler::TOUCHSCREEN)
                .thread);
  scroll_result = host_impl_->ScrollBy(
      UpdateState(gfx::Point(), gfx::Vector2dF(0, 100)).get());
  EXPECT_VECTOR_EQ(gfx::Vector2dF(), inner_scroll->CurrentScrollOffset());

  // When inner viewport is unscrollable, a fling gives zero overscroll.
  EXPECT_FALSE(scroll_result.did_overscroll_root);
  EXPECT_EQ(gfx::Vector2dF(), host_impl_->accumulated_root_overscroll());
}

class LayerTreeHostImplWithImplicitLimitsTest : public LayerTreeHostImplTest {
 public:
  void SetUp() override {
    LayerTreeSettings settings = DefaultSettings();
    settings.max_memory_for_prepaint_percentage = 50;
    CreateHostImpl(settings, CreateOutputSurface());
  }
};

TEST_F(LayerTreeHostImplWithImplicitLimitsTest, ImplicitMemoryLimits) {
  // Set up a memory policy and percentages which could cause
  // 32-bit integer overflows.
  ManagedMemoryPolicy mem_policy(300 * 1024 * 1024);  // 300MB

  // Verify implicit limits are calculated correctly with no overflows
  host_impl_->SetMemoryPolicy(mem_policy);
  EXPECT_EQ(host_impl_->global_tile_state().hard_memory_limit_in_bytes,
            300u * 1024u * 1024u);
  EXPECT_EQ(host_impl_->global_tile_state().soft_memory_limit_in_bytes,
            150u * 1024u * 1024u);
}

TEST_F(LayerTreeHostImplTest, ExternalTransformReflectedInNextDraw) {
  const gfx::Size layer_size(100, 100);
  gfx::Transform external_transform;
  const gfx::Rect external_viewport(layer_size);
  const gfx::Rect external_clip(layer_size);
  const bool resourceless_software_draw = false;
  LayerImpl* layer = SetupScrollAndContentsLayers(layer_size);
  layer->SetDrawsContent(true);

  host_impl_->SetExternalTilePriorityConstraints(external_viewport,
                                                 external_transform);
  host_impl_->OnDraw(external_transform, external_viewport, external_clip,
                     resourceless_software_draw);
  EXPECT_TRANSFORMATION_MATRIX_EQ(
      external_transform, layer->draw_properties().target_space_transform);

  external_transform.Translate(20, 20);
  host_impl_->SetExternalTilePriorityConstraints(external_viewport,
                                                 external_transform);
  host_impl_->OnDraw(external_transform, external_viewport, external_clip,
                     resourceless_software_draw);
  EXPECT_TRANSFORMATION_MATRIX_EQ(
      external_transform, layer->draw_properties().target_space_transform);
}

TEST_F(LayerTreeHostImplTest, ExternalTransformSetNeedsRedraw) {
  SetupRootLayerImpl(LayerImpl::Create(host_impl_->active_tree(), 1));

  const gfx::Size viewport_size(100, 100);
  host_impl_->SetViewportSize(viewport_size);

  const gfx::Transform transform_for_tile_priority;
  const gfx::Transform draw_transform;
  const gfx::Rect viewport_for_tile_priority1(viewport_size);
  const gfx::Rect viewport_for_tile_priority2(50, 50);
  const gfx::Rect draw_viewport(viewport_size);
  const gfx::Rect clip(viewport_size);
  bool resourceless_software_draw = false;

  // Clear any damage.
  host_impl_->SetExternalTilePriorityConstraints(viewport_for_tile_priority1,
                                                 transform_for_tile_priority);
  host_impl_->OnDraw(draw_transform, draw_viewport, clip,
                     resourceless_software_draw);
  last_on_draw_frame_.reset();

  // Setting new constraints needs redraw.
  did_request_redraw_ = false;
  host_impl_->SetExternalTilePriorityConstraints(viewport_for_tile_priority2,
                                                 transform_for_tile_priority);
  EXPECT_TRUE(did_request_redraw_);
  host_impl_->OnDraw(draw_transform, draw_viewport, clip,
                     resourceless_software_draw);
  EXPECT_FALSE(last_on_draw_frame_->has_no_damage);
}

TEST_F(LayerTreeHostImplTest, OnDrawConstraintSetNeedsRedraw) {
  SetupRootLayerImpl(LayerImpl::Create(host_impl_->active_tree(), 1));

  const gfx::Size viewport_size(100, 100);
  host_impl_->SetViewportSize(viewport_size);

  const gfx::Transform draw_transform;
  const gfx::Rect draw_viewport1(viewport_size);
  const gfx::Rect draw_viewport2(50, 50);
  const gfx::Rect clip(viewport_size);
  bool resourceless_software_draw = false;

  // Clear any damage.
  host_impl_->OnDraw(draw_transform, draw_viewport1, clip,
                     resourceless_software_draw);
  last_on_draw_frame_.reset();

  // Same draw params does not swap.
  did_request_redraw_ = false;
  host_impl_->OnDraw(draw_transform, draw_viewport1, clip,
                     resourceless_software_draw);
  EXPECT_FALSE(did_request_redraw_);
  EXPECT_TRUE(last_on_draw_frame_->has_no_damage);
  last_on_draw_frame_.reset();

  // Different draw params does swap.
  did_request_redraw_ = false;
  host_impl_->OnDraw(draw_transform, draw_viewport2, clip,
                     resourceless_software_draw);
  EXPECT_TRUE(did_request_redraw_);
  EXPECT_FALSE(last_on_draw_frame_->has_no_damage);
}

class ResourcelessSoftwareLayerTreeHostImplTest : public LayerTreeHostImplTest {
 protected:
  scoped_ptr<OutputSurface> CreateOutputSurface() override {
    return FakeOutputSurface::Create3dWithResourcelessSoftwareSupport();
  }
};

TEST_F(ResourcelessSoftwareLayerTreeHostImplTest,
       ResourcelessSoftwareSetNeedsRedraw) {
  SetupRootLayerImpl(LayerImpl::Create(host_impl_->active_tree(), 1));

  const gfx::Size viewport_size(100, 100);
  host_impl_->SetViewportSize(viewport_size);

  const gfx::Transform draw_transform;
  const gfx::Rect draw_viewport(viewport_size);
  const gfx::Rect clip(viewport_size);
  bool resourceless_software_draw = false;

  // Clear any damage.
  host_impl_->OnDraw(draw_transform, draw_viewport, clip,
                     resourceless_software_draw);
  last_on_draw_frame_.reset();

  // Always swap even if same draw params.
  resourceless_software_draw = true;
  host_impl_->OnDraw(draw_transform, draw_viewport, clip,
                     resourceless_software_draw);
  EXPECT_FALSE(last_on_draw_frame_->has_no_damage);
  last_on_draw_frame_.reset();

  // Next hardware draw has damage.
  resourceless_software_draw = false;
  host_impl_->OnDraw(draw_transform, draw_viewport, clip,
                     resourceless_software_draw);
  EXPECT_FALSE(last_on_draw_frame_->has_no_damage);
}

TEST_F(ResourcelessSoftwareLayerTreeHostImplTest,
       ResourcelessSoftwareDrawSkipsUpdateTiles) {
  const gfx::Size viewport_size(100, 100);
  host_impl_->SetViewportSize(viewport_size);

  host_impl_->CreatePendingTree();
  scoped_refptr<FakeDisplayListRasterSource> raster_source(
      FakeDisplayListRasterSource::CreateFilled(viewport_size));
  scoped_ptr<FakePictureLayerImpl> layer(
      FakePictureLayerImpl::CreateWithRasterSource(host_impl_->pending_tree(),
                                                   11, raster_source));
  layer->SetBounds(viewport_size);
  layer->SetDrawsContent(true);
  host_impl_->pending_tree()->SetRootLayer(std::move(layer));

  host_impl_->pending_tree()->BuildPropertyTreesForTesting();
  host_impl_->ActivateSyncTree();

  const gfx::Transform draw_transform;
  const gfx::Rect draw_viewport(viewport_size);
  const gfx::Rect clip(viewport_size);
  bool resourceless_software_draw = false;

  // Regular draw causes UpdateTiles.
  did_request_prepare_tiles_ = false;
  host_impl_->OnDraw(draw_transform, draw_viewport, clip,
                     resourceless_software_draw);
  EXPECT_TRUE(did_request_prepare_tiles_);
  host_impl_->PrepareTiles();

  // Resourceless draw skips UpdateTiles.
  const gfx::Rect new_draw_viewport(50, 50);
  resourceless_software_draw = true;
  did_request_prepare_tiles_ = false;
  host_impl_->OnDraw(draw_transform, new_draw_viewport, clip,
                     resourceless_software_draw);
  EXPECT_FALSE(did_request_prepare_tiles_);
}

TEST_F(LayerTreeHostImplTest, ExternalTileConstraintReflectedInPendingTree) {
  EXPECT_FALSE(host_impl_->CommitToActiveTree());
  const gfx::Size layer_size(100, 100);
  host_impl_->SetViewportSize(layer_size);
  bool update_lcd_text = false;

  // Set up active and pending tree.
  host_impl_->CreatePendingTree();
  host_impl_->pending_tree()->SetRootLayer(
      LayerImpl::Create(host_impl_->pending_tree(), 1));
  host_impl_->pending_tree()->BuildPropertyTreesForTesting();
  host_impl_->pending_tree()->UpdateDrawProperties(update_lcd_text);

  host_impl_->ActivateSyncTree();
  host_impl_->active_tree()->BuildPropertyTreesForTesting();
  host_impl_->active_tree()->UpdateDrawProperties(update_lcd_text);

  host_impl_->CreatePendingTree();
  host_impl_->pending_tree()->UpdateDrawProperties(update_lcd_text);
  host_impl_->active_tree()->UpdateDrawProperties(update_lcd_text);

  EXPECT_FALSE(host_impl_->pending_tree()->needs_update_draw_properties());
  EXPECT_FALSE(host_impl_->active_tree()->needs_update_draw_properties());

  // Update external constraints should set_needs_update_draw_properties on
  // both trees.
  gfx::Transform external_transform;
  gfx::Rect external_viewport(10, 20);
  host_impl_->SetExternalTilePriorityConstraints(external_viewport,
                                                 external_transform);
  EXPECT_TRUE(host_impl_->pending_tree()->needs_update_draw_properties());
  EXPECT_TRUE(host_impl_->active_tree()->needs_update_draw_properties());
}

TEST_F(LayerTreeHostImplTest, ExternalViewportAffectsVisibleRects) {
  const gfx::Size layer_size(100, 100);
  SetupScrollAndContentsLayers(layer_size);
  LayerImpl* content_layer = host_impl_->active_tree()
                                 ->OuterViewportScrollLayer()
                                 ->children()[0]
                                 .get();
  SetNeedsRebuildPropertyTrees();
  RebuildPropertyTrees();

  bool update_lcd_text = false;

  host_impl_->SetViewportSize(gfx::Size(90, 90));
  host_impl_->active_tree()->UpdateDrawProperties(update_lcd_text);
  EXPECT_EQ(gfx::Rect(90, 90), content_layer->visible_layer_rect());

  gfx::Transform external_transform;
  gfx::Rect external_viewport(10, 20);
  gfx::Rect external_clip(layer_size);
  bool resourceless_software_draw = false;
  host_impl_->SetExternalTilePriorityConstraints(external_viewport,
                                                 external_transform);
  host_impl_->OnDraw(external_transform, external_viewport, external_clip,
                     resourceless_software_draw);
  EXPECT_EQ(gfx::Rect(10, 20), content_layer->visible_layer_rect());

  // Clear the external viewport.
  external_viewport = gfx::Rect();
  host_impl_->SetExternalTilePriorityConstraints(external_viewport,
                                                 external_transform);

  host_impl_->OnDraw(external_transform, external_viewport, external_clip,
                     resourceless_software_draw);
  EXPECT_EQ(gfx::Rect(90, 90), content_layer->visible_layer_rect());
}

TEST_F(LayerTreeHostImplTest, ExternalTransformAffectsVisibleRects) {
  const gfx::Size layer_size(100, 100);
  SetupScrollAndContentsLayers(layer_size);
  LayerImpl* content_layer = host_impl_->active_tree()
                                 ->OuterViewportScrollLayer()
                                 ->children()[0]
                                 .get();
  SetNeedsRebuildPropertyTrees();
  RebuildPropertyTrees();

  bool update_lcd_text = false;

  host_impl_->SetViewportSize(gfx::Size(50, 50));
  host_impl_->active_tree()->UpdateDrawProperties(update_lcd_text);
  EXPECT_EQ(gfx::Rect(50, 50), content_layer->visible_layer_rect());

  gfx::Transform external_transform;
  external_transform.Translate(10, 10);
  external_transform.Scale(2, 2);
  gfx::Rect external_viewport;
  gfx::Rect external_clip(layer_size);
  bool resourceless_software_draw = false;
  host_impl_->SetExternalTilePriorityConstraints(external_viewport,
                                                 external_transform);

  // Visible rects should now be shifted and scaled because of the external
  // transform.
  host_impl_->OnDraw(external_transform, external_viewport, external_clip,
                     resourceless_software_draw);
  EXPECT_EQ(gfx::Rect(20, 20), content_layer->visible_layer_rect());

  // Clear the external transform.
  external_transform = gfx::Transform();
  host_impl_->SetExternalTilePriorityConstraints(external_viewport,
                                                 external_transform);

  host_impl_->OnDraw(external_transform, external_viewport, external_clip,
                     resourceless_software_draw);
  EXPECT_EQ(gfx::Rect(50, 50), content_layer->visible_layer_rect());
}

TEST_F(LayerTreeHostImplTest, ExternalTransformAffectsSublayerScaleFactor) {
  const gfx::Size layer_size(100, 100);
  SetupScrollAndContentsLayers(layer_size);
  LayerImpl* content_layer = host_impl_->active_tree()
                                 ->OuterViewportScrollLayer()
                                 ->children()[0]
                                 .get();
  content_layer->AddChild(LayerImpl::Create(host_impl_->active_tree(), 100));
  LayerImpl* test_layer = host_impl_->active_tree()->LayerById(100);
  test_layer->SetForceRenderSurface(true);
  test_layer->SetDrawsContent(true);
  test_layer->SetBounds(layer_size);
  gfx::Transform perspective_transform;
  perspective_transform.ApplyPerspectiveDepth(2);
  test_layer->SetTransform(perspective_transform);

  SetNeedsRebuildPropertyTrees();
  RebuildPropertyTrees();
  bool update_lcd_text = false;

  host_impl_->SetViewportSize(gfx::Size(50, 50));
  host_impl_->active_tree()->UpdateDrawProperties(update_lcd_text);
  TransformNode* node =
      host_impl_->active_tree()->property_trees()->transform_tree.Node(
          test_layer->transform_tree_index());
  EXPECT_EQ(node->data.sublayer_scale, gfx::Vector2dF(1.f, 1.f));

  gfx::Transform external_transform;
  external_transform.Translate(10, 10);
  external_transform.Scale(2, 2);
  gfx::Rect external_viewport;
  gfx::Rect external_clip(layer_size);
  bool resourceless_software_draw = false;
  host_impl_->SetExternalTilePriorityConstraints(external_viewport,
                                                 external_transform);

  // Transform node's sublayer scale should include the device transform scale.
  host_impl_->OnDraw(external_transform, external_viewport, external_clip,
                     resourceless_software_draw);
  node = host_impl_->active_tree()->property_trees()->transform_tree.Node(
      test_layer->transform_tree_index());
  EXPECT_EQ(node->data.sublayer_scale, gfx::Vector2dF(2.f, 2.f));

  // Clear the external transform.
  external_transform = gfx::Transform();
  host_impl_->SetExternalTilePriorityConstraints(external_viewport,
                                                 external_transform);

  host_impl_->OnDraw(external_transform, external_viewport, external_clip,
                     resourceless_software_draw);
  node = host_impl_->active_tree()->property_trees()->transform_tree.Node(
      test_layer->transform_tree_index());
  EXPECT_EQ(node->data.sublayer_scale, gfx::Vector2dF(1.f, 1.f));
}

TEST_F(LayerTreeHostImplTest, ScrollAnimated) {
  SetupScrollAndContentsLayers(gfx::Size(100, 200));

  // Shrink the outer viewport clip layer so that the outer viewport can scroll.
  host_impl_->OuterViewportScrollLayer()->parent()->SetBounds(
      gfx::Size(50, 100));

  SetNeedsRebuildPropertyTrees();
  DrawFrame();

  base::TimeTicks start_time =
      base::TimeTicks() + base::TimeDelta::FromMilliseconds(100);

  BeginFrameArgs begin_frame_args =
      CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE);

  EXPECT_EQ(
      InputHandler::SCROLL_ON_IMPL_THREAD,
      host_impl_->ScrollAnimated(gfx::Point(), gfx::Vector2d(0, 50)).thread);

  LayerImpl* scrolling_layer = host_impl_->CurrentlyScrollingLayer();
  EXPECT_EQ(host_impl_->OuterViewportScrollLayer(), scrolling_layer);

  begin_frame_args.frame_time = start_time;
  host_impl_->WillBeginImplFrame(begin_frame_args);
  host_impl_->Animate();
  host_impl_->UpdateAnimationState(true);

  EXPECT_EQ(gfx::ScrollOffset(), scrolling_layer->CurrentScrollOffset());
  host_impl_->DidFinishImplFrame();

  begin_frame_args.frame_time =
      start_time + base::TimeDelta::FromMilliseconds(50);
  host_impl_->WillBeginImplFrame(begin_frame_args);
  host_impl_->Animate();
  host_impl_->UpdateAnimationState(true);

  float y = scrolling_layer->CurrentScrollOffset().y();
  EXPECT_TRUE(y > 1 && y < 49);

  // Update target.
  EXPECT_EQ(
      InputHandler::SCROLL_ON_IMPL_THREAD,
      host_impl_->ScrollAnimated(gfx::Point(), gfx::Vector2d(0, 50)).thread);
  host_impl_->DidFinishImplFrame();

  begin_frame_args.frame_time =
      start_time + base::TimeDelta::FromMilliseconds(200);
  host_impl_->WillBeginImplFrame(begin_frame_args);
  host_impl_->Animate();
  host_impl_->UpdateAnimationState(true);

  y = scrolling_layer->CurrentScrollOffset().y();
  EXPECT_TRUE(y > 50 && y < 100);
  EXPECT_EQ(scrolling_layer, host_impl_->CurrentlyScrollingLayer());
  host_impl_->DidFinishImplFrame();

  begin_frame_args.frame_time =
      start_time + base::TimeDelta::FromMilliseconds(250);
  host_impl_->WillBeginImplFrame(begin_frame_args);
  host_impl_->Animate();
  host_impl_->UpdateAnimationState(true);

  EXPECT_VECTOR_EQ(gfx::ScrollOffset(0, 100),
                   scrolling_layer->CurrentScrollOffset());
  EXPECT_EQ(NULL, host_impl_->CurrentlyScrollingLayer());
  host_impl_->DidFinishImplFrame();
}

// Test that a smooth scroll offset animation is aborted when followed by a
// non-smooth scroll offset animation.
TEST_F(LayerTreeHostImplTimelinesTest, ScrollAnimatedAborted) {
  const gfx::Size content_size(1000, 1000);
  const gfx::Size viewport_size(500, 500);
  CreateBasicVirtualViewportLayers(viewport_size, content_size);

  DrawFrame();

  base::TimeTicks start_time =
      base::TimeTicks() + base::TimeDelta::FromMilliseconds(100);

  BeginFrameArgs begin_frame_args =
      CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE);

  // Perform animated scroll.
  EXPECT_EQ(
      InputHandler::SCROLL_ON_IMPL_THREAD,
      host_impl_->ScrollAnimated(gfx::Point(), gfx::Vector2d(0, 50)).thread);

  LayerImpl* scrolling_layer = host_impl_->CurrentlyScrollingLayer();

  begin_frame_args.frame_time = start_time;
  host_impl_->WillBeginImplFrame(begin_frame_args);
  host_impl_->Animate();
  host_impl_->UpdateAnimationState(true);

  EXPECT_TRUE(host_impl_->animation_host()->HasAnyAnimationTargetingProperty(
      scrolling_layer->id(), TargetProperty::SCROLL_OFFSET));

  EXPECT_EQ(gfx::ScrollOffset(), scrolling_layer->CurrentScrollOffset());
  host_impl_->DidFinishImplFrame();

  begin_frame_args.frame_time =
      start_time + base::TimeDelta::FromMilliseconds(50);
  host_impl_->WillBeginImplFrame(begin_frame_args);
  host_impl_->Animate();
  host_impl_->UpdateAnimationState(true);

  float y = scrolling_layer->CurrentScrollOffset().y();
  EXPECT_TRUE(y > 1 && y < 49);

  // Perform instant scroll.
  EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
            host_impl_->ScrollBegin(BeginState(gfx::Point(0, y)).get(),
                                    InputHandler::WHEEL)
                .thread);
  EXPECT_TRUE(host_impl_->IsCurrentlyScrollingLayerAt(gfx::Point(0, y),
                                                      InputHandler::WHEEL));
  host_impl_->ScrollBy(
      UpdateState(gfx::Point(0, y), gfx::Vector2d(0, 50)).get());
  EXPECT_TRUE(host_impl_->IsCurrentlyScrollingLayerAt(gfx::Point(0, y + 50),
                                                      InputHandler::WHEEL));
  scoped_ptr<ScrollState> scroll_state_end = EndState();
  host_impl_->ScrollEnd(scroll_state_end.get());
  EXPECT_FALSE(host_impl_->IsCurrentlyScrollingLayerAt(gfx::Point(),
                                                       InputHandler::WHEEL));

  // The instant scroll should have marked the smooth scroll animation as
  // aborted.
  EXPECT_FALSE(host_impl_->animation_host()->HasActiveAnimationForTesting(
      scrolling_layer->id()));

  EXPECT_VECTOR2DF_EQ(gfx::ScrollOffset(0, y + 50),
                      scrolling_layer->CurrentScrollOffset());
  EXPECT_EQ(NULL, host_impl_->CurrentlyScrollingLayer());
  host_impl_->DidFinishImplFrame();
}

// Test that a smooth scroll offset animation is marked finished when a main
// thread scrolling reason is added. The animation is then finished on the
// main thread.
TEST_F(LayerTreeHostImplTimelinesTest,
       ScrollAnimatedFinishedByMainThreadScrollingReason) {
  const gfx::Size content_size(1000, 1000);
  const gfx::Size viewport_size(500, 500);
  CreateBasicVirtualViewportLayers(viewport_size, content_size);

  DrawFrame();

  base::TimeTicks start_time =
      base::TimeTicks() + base::TimeDelta::FromMilliseconds(100);

  BeginFrameArgs begin_frame_args =
      CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE);

  // Perform animated scroll.
  EXPECT_EQ(
      InputHandler::SCROLL_ON_IMPL_THREAD,
      host_impl_->ScrollAnimated(gfx::Point(), gfx::Vector2d(0, 100)).thread);

  LayerImpl* scrolling_layer = host_impl_->CurrentlyScrollingLayer();

  begin_frame_args.frame_time = start_time;
  host_impl_->WillBeginImplFrame(begin_frame_args);
  host_impl_->Animate();
  host_impl_->UpdateAnimationState(true);

  EXPECT_TRUE(host_impl_->animation_host()->HasAnyAnimationTargetingProperty(
      scrolling_layer->id(), TargetProperty::SCROLL_OFFSET));

  EXPECT_EQ(gfx::ScrollOffset(), scrolling_layer->CurrentScrollOffset());
  host_impl_->DidFinishImplFrame();

  begin_frame_args.frame_time =
      start_time + base::TimeDelta::FromMilliseconds(50);
  host_impl_->WillBeginImplFrame(begin_frame_args);
  host_impl_->Animate();
  host_impl_->UpdateAnimationState(true);

  float y = scrolling_layer->CurrentScrollOffset().y();
  EXPECT_TRUE(y > 1 && y < 49);

  // Add main thread scrolling reason.
  scrolling_layer->set_main_thread_scrolling_reasons(
      MainThreadScrollingReason::kHasNonLayerViewportConstrainedObjects);
  host_impl_->UpdateAnimationState(true);

  // The main thread scrolling reason should have marked the smooth scroll
  // animation as finished.
  EXPECT_FALSE(host_impl_->animation_host()->HasActiveAnimationForTesting(
      scrolling_layer->id()));
  EXPECT_TRUE(y > 1 && y < 49);
  EXPECT_EQ(NULL, host_impl_->CurrentlyScrollingLayer());
  host_impl_->DidFinishImplFrame();
}

// Evolved from LayerTreeHostImplTest.ScrollAnimated.
TEST_F(LayerTreeHostImplTimelinesTest, ScrollAnimated) {
  const gfx::Size content_size(1000, 1000);
  const gfx::Size viewport_size(500, 500);
  CreateBasicVirtualViewportLayers(viewport_size, content_size);

  SetNeedsRebuildPropertyTrees();
  DrawFrame();

  base::TimeTicks start_time =
      base::TimeTicks() + base::TimeDelta::FromMilliseconds(100);

  BeginFrameArgs begin_frame_args =
      CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE);

  EXPECT_EQ(
      InputHandler::SCROLL_ON_IMPL_THREAD,
      host_impl_->ScrollAnimated(gfx::Point(), gfx::Vector2d(0, 50)).thread);

  LayerImpl* scrolling_layer = host_impl_->CurrentlyScrollingLayer();
  begin_frame_args.frame_time = start_time;
  host_impl_->WillBeginImplFrame(begin_frame_args);
  host_impl_->Animate();
  host_impl_->UpdateAnimationState(true);

  EXPECT_EQ(gfx::ScrollOffset(), scrolling_layer->CurrentScrollOffset());
  host_impl_->DidFinishImplFrame();

  begin_frame_args.frame_time =
      start_time + base::TimeDelta::FromMilliseconds(50);
  host_impl_->WillBeginImplFrame(begin_frame_args);
  host_impl_->Animate();
  host_impl_->UpdateAnimationState(true);

  float y = scrolling_layer->CurrentScrollOffset().y();
  EXPECT_TRUE(y > 1 && y < 49);

  // Update target.
  EXPECT_EQ(
      InputHandler::SCROLL_ON_IMPL_THREAD,
      host_impl_->ScrollAnimated(gfx::Point(), gfx::Vector2d(0, 50)).thread);
  host_impl_->DidFinishImplFrame();

  begin_frame_args.frame_time =
      start_time + base::TimeDelta::FromMilliseconds(200);
  host_impl_->WillBeginImplFrame(begin_frame_args);
  host_impl_->Animate();
  host_impl_->UpdateAnimationState(true);

  y = scrolling_layer->CurrentScrollOffset().y();
  EXPECT_TRUE(y > 50 && y < 100);
  EXPECT_EQ(scrolling_layer, host_impl_->CurrentlyScrollingLayer());
  host_impl_->DidFinishImplFrame();

  begin_frame_args.frame_time =
      start_time + base::TimeDelta::FromMilliseconds(250);
  host_impl_->WillBeginImplFrame(begin_frame_args);
  host_impl_->Animate();
  host_impl_->UpdateAnimationState(true);

  EXPECT_VECTOR_EQ(gfx::ScrollOffset(0, 100),
                   scrolling_layer->CurrentScrollOffset());
  EXPECT_EQ(NULL, host_impl_->CurrentlyScrollingLayer());
  host_impl_->DidFinishImplFrame();
}

// Test that smooth scroll offset animation doesn't happen for non user
// scrollable layers.
TEST_F(LayerTreeHostImplTimelinesTest, ScrollAnimatedNotUserScrollable) {
  const gfx::Size content_size(1000, 1000);
  const gfx::Size viewport_size(500, 500);
  CreateBasicVirtualViewportLayers(viewport_size, content_size);

  host_impl_->OuterViewportScrollLayer()->set_user_scrollable_vertical(true);
  host_impl_->OuterViewportScrollLayer()->set_user_scrollable_horizontal(false);

  SetNeedsRebuildPropertyTrees();
  DrawFrame();

  base::TimeTicks start_time =
      base::TimeTicks() + base::TimeDelta::FromMilliseconds(100);

  BeginFrameArgs begin_frame_args =
      CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE);

  EXPECT_EQ(
      InputHandler::SCROLL_ON_IMPL_THREAD,
      host_impl_->ScrollAnimated(gfx::Point(), gfx::Vector2d(50, 50)).thread);

  LayerImpl* scrolling_layer = host_impl_->CurrentlyScrollingLayer();
  begin_frame_args.frame_time = start_time;
  host_impl_->WillBeginImplFrame(begin_frame_args);
  host_impl_->Animate();
  host_impl_->UpdateAnimationState(true);

  EXPECT_EQ(gfx::ScrollOffset(), scrolling_layer->CurrentScrollOffset());
  host_impl_->DidFinishImplFrame();

  begin_frame_args.frame_time =
      start_time + base::TimeDelta::FromMilliseconds(50);
  host_impl_->WillBeginImplFrame(begin_frame_args);
  host_impl_->Animate();
  host_impl_->UpdateAnimationState(true);

  // Should not have scrolled horizontally.
  EXPECT_EQ(0, scrolling_layer->CurrentScrollOffset().x());
  float y = scrolling_layer->CurrentScrollOffset().y();
  EXPECT_TRUE(y > 1 && y < 49);

  // Update target.
  EXPECT_EQ(
      InputHandler::SCROLL_ON_IMPL_THREAD,
      host_impl_->ScrollAnimated(gfx::Point(), gfx::Vector2d(50, 50)).thread);
  host_impl_->DidFinishImplFrame();

  begin_frame_args.frame_time =
      start_time + base::TimeDelta::FromMilliseconds(200);
  host_impl_->WillBeginImplFrame(begin_frame_args);
  host_impl_->Animate();
  host_impl_->UpdateAnimationState(true);

  y = scrolling_layer->CurrentScrollOffset().y();
  EXPECT_TRUE(y > 50 && y < 100);
  EXPECT_EQ(scrolling_layer, host_impl_->CurrentlyScrollingLayer());
  host_impl_->DidFinishImplFrame();

  begin_frame_args.frame_time =
      start_time + base::TimeDelta::FromMilliseconds(250);
  host_impl_->WillBeginImplFrame(begin_frame_args);
  host_impl_->Animate();
  host_impl_->UpdateAnimationState(true);

  EXPECT_VECTOR_EQ(gfx::ScrollOffset(0, 100),
                   scrolling_layer->CurrentScrollOffset());
  EXPECT_EQ(NULL, host_impl_->CurrentlyScrollingLayer());
  host_impl_->DidFinishImplFrame();
}

TEST_F(LayerTreeHostImplTest, InvalidLayerNotAddedToRasterQueue) {
  host_impl_->CreatePendingTree();

  Region empty_invalidation;
  scoped_refptr<DisplayListRasterSource> raster_source_with_tiles(
      FakeDisplayListRasterSource::CreateFilled(gfx::Size(10, 10)));

  scoped_ptr<FakePictureLayerImpl> layer =
      FakePictureLayerImpl::Create(host_impl_->pending_tree(), 11);
  layer->SetBounds(gfx::Size(10, 10));
  layer->set_gpu_raster_max_texture_size(host_impl_->device_viewport_size());
  layer->SetDrawsContent(true);
  layer->tilings()->AddTiling(1.0f, raster_source_with_tiles);
  layer->UpdateRasterSource(raster_source_with_tiles, &empty_invalidation,
                            nullptr);
  layer->tilings()->tiling_at(0)->set_resolution(
      TileResolution::HIGH_RESOLUTION);
  layer->tilings()->tiling_at(0)->CreateAllTilesForTesting();
  layer->tilings()->tiling_at(0)->ComputeTilePriorityRects(
      gfx::Rect(gfx::Size(10, 10)), 1.f, 1.0, Occlusion());
  host_impl_->pending_tree()->SetRootLayer(std::move(layer));

  FakePictureLayerImpl* root_layer = static_cast<FakePictureLayerImpl*>(
      host_impl_->pending_tree()->root_layer());

  root_layer->set_has_valid_tile_priorities(true);
  scoped_ptr<RasterTilePriorityQueue> non_empty_raster_priority_queue_all =
      host_impl_->BuildRasterQueue(TreePriority::SAME_PRIORITY_FOR_BOTH_TREES,
                                   RasterTilePriorityQueue::Type::ALL);
  EXPECT_FALSE(non_empty_raster_priority_queue_all->IsEmpty());

  root_layer->set_has_valid_tile_priorities(false);
  scoped_ptr<RasterTilePriorityQueue> empty_raster_priority_queue_all =
      host_impl_->BuildRasterQueue(TreePriority::SAME_PRIORITY_FOR_BOTH_TREES,
                                   RasterTilePriorityQueue::Type::ALL);
  EXPECT_TRUE(empty_raster_priority_queue_all->IsEmpty());
}

TEST_F(LayerTreeHostImplTest, DidBecomeActive) {
  host_impl_->CreatePendingTree();
  host_impl_->ActivateSyncTree();
  host_impl_->CreatePendingTree();

  LayerTreeImpl* pending_tree = host_impl_->pending_tree();

  scoped_ptr<FakePictureLayerImpl> pending_layer =
      FakePictureLayerImpl::Create(pending_tree, 10);
  FakePictureLayerImpl* raw_pending_layer = pending_layer.get();
  pending_tree->SetRootLayer(std::move(pending_layer));
  ASSERT_EQ(raw_pending_layer, pending_tree->root_layer());

  EXPECT_EQ(0u, raw_pending_layer->did_become_active_call_count());
  pending_tree->DidBecomeActive();
  EXPECT_EQ(1u, raw_pending_layer->did_become_active_call_count());

  scoped_ptr<FakePictureLayerImpl> mask_layer =
      FakePictureLayerImpl::Create(pending_tree, 11);
  FakePictureLayerImpl* raw_mask_layer = mask_layer.get();
  raw_pending_layer->SetMaskLayer(std::move(mask_layer));
  ASSERT_EQ(raw_mask_layer, raw_pending_layer->mask_layer());

  EXPECT_EQ(1u, raw_pending_layer->did_become_active_call_count());
  EXPECT_EQ(0u, raw_mask_layer->did_become_active_call_count());
  pending_tree->DidBecomeActive();
  EXPECT_EQ(2u, raw_pending_layer->did_become_active_call_count());
  EXPECT_EQ(1u, raw_mask_layer->did_become_active_call_count());

  scoped_ptr<FakePictureLayerImpl> replica_layer =
      FakePictureLayerImpl::Create(pending_tree, 12);
  scoped_ptr<FakePictureLayerImpl> replica_mask_layer =
      FakePictureLayerImpl::Create(pending_tree, 13);
  FakePictureLayerImpl* raw_replica_mask_layer = replica_mask_layer.get();
  replica_layer->SetMaskLayer(std::move(replica_mask_layer));
  raw_pending_layer->SetReplicaLayer(std::move(replica_layer));
  ASSERT_EQ(raw_replica_mask_layer,
            raw_pending_layer->replica_layer()->mask_layer());

  EXPECT_EQ(2u, raw_pending_layer->did_become_active_call_count());
  EXPECT_EQ(1u, raw_mask_layer->did_become_active_call_count());
  EXPECT_EQ(0u, raw_replica_mask_layer->did_become_active_call_count());
  pending_tree->DidBecomeActive();
  EXPECT_EQ(3u, raw_pending_layer->did_become_active_call_count());
  EXPECT_EQ(2u, raw_mask_layer->did_become_active_call_count());
  EXPECT_EQ(1u, raw_replica_mask_layer->did_become_active_call_count());
}

TEST_F(LayerTreeHostImplTest, WheelScrollWithPageScaleFactorOnInnerLayer) {
  LayerImpl* scroll_layer = SetupScrollAndContentsLayers(gfx::Size(100, 100));
  host_impl_->SetViewportSize(gfx::Size(50, 50));
  DrawFrame();

  EXPECT_EQ(scroll_layer, host_impl_->InnerViewportScrollLayer());

  float min_page_scale = 1.f, max_page_scale = 4.f;
  float page_scale_factor = 1.f;

  // The scroll deltas should have the page scale factor applied.
  {
    host_impl_->active_tree()->PushPageScaleFromMainThread(
        page_scale_factor, min_page_scale, max_page_scale);
    host_impl_->active_tree()->SetPageScaleOnActiveTree(page_scale_factor);
    SetScrollOffsetDelta(scroll_layer, gfx::Vector2d());

    float page_scale_delta = 2.f;
    host_impl_->ScrollBegin(BeginState(gfx::Point()).get(),
                            InputHandler::TOUCHSCREEN);
    host_impl_->PinchGestureBegin();
    host_impl_->PinchGestureUpdate(page_scale_delta, gfx::Point());
    host_impl_->PinchGestureEnd();
    host_impl_->ScrollEnd(EndState().get());

    gfx::Vector2dF scroll_delta(0, 5);
    EXPECT_EQ(InputHandler::SCROLL_ON_IMPL_THREAD,
              host_impl_->ScrollBegin(BeginState(gfx::Point()).get(),
                                      InputHandler::WHEEL)
                  .thread);
    EXPECT_VECTOR_EQ(gfx::Vector2dF(), scroll_layer->CurrentScrollOffset());

    host_impl_->ScrollBy(UpdateState(gfx::Point(), scroll_delta).get());
    host_impl_->ScrollEnd(EndState().get());
    EXPECT_VECTOR_EQ(gfx::Vector2dF(0, 2.5),
                     scroll_layer->CurrentScrollOffset());
  }
}

class LayerTreeHostImplCountingLostSurfaces : public LayerTreeHostImplTest {
 public:
  LayerTreeHostImplCountingLostSurfaces() : num_lost_surfaces_(0) {}
  void DidLoseOutputSurfaceOnImplThread() override { num_lost_surfaces_++; }

 protected:
  int num_lost_surfaces_;
};

TEST_F(LayerTreeHostImplCountingLostSurfaces, TwiceLostSurface) {
  // Really we just need at least one client notification each time
  // we go from having a valid output surface to not having a valid output
  // surface.
  EXPECT_EQ(0, num_lost_surfaces_);
  host_impl_->DidLoseOutputSurface();
  EXPECT_EQ(1, num_lost_surfaces_);
  host_impl_->DidLoseOutputSurface();
  EXPECT_LE(1, num_lost_surfaces_);
}

size_t CountRenderPassesWithId(const RenderPassList& list, RenderPassId id) {
  return std::count_if(
      list.begin(), list.end(),
      [id](const scoped_ptr<RenderPass>& p) { return p->id == id; });
}

TEST_F(LayerTreeHostImplTest, RemoveUnreferencedRenderPass) {
  LayerTreeHostImpl::FrameData frame;
  frame.render_passes.push_back(RenderPass::Create());
  RenderPass* pass3 = frame.render_passes.back().get();
  frame.render_passes.push_back(RenderPass::Create());
  RenderPass* pass2 = frame.render_passes.back().get();
  frame.render_passes.push_back(RenderPass::Create());
  RenderPass* pass1 = frame.render_passes.back().get();

  pass1->SetNew(RenderPassId(1, 0), gfx::Rect(), gfx::Rect(), gfx::Transform());
  pass2->SetNew(RenderPassId(2, 0), gfx::Rect(), gfx::Rect(), gfx::Transform());
  pass3->SetNew(RenderPassId(3, 0), gfx::Rect(), gfx::Rect(), gfx::Transform());

  // Add a quad to each pass so they aren't empty.
  SolidColorDrawQuad* color_quad;
  color_quad = pass1->CreateAndAppendDrawQuad<SolidColorDrawQuad>();
  color_quad->material = DrawQuad::SOLID_COLOR;
  color_quad = pass2->CreateAndAppendDrawQuad<SolidColorDrawQuad>();
  color_quad->material = DrawQuad::SOLID_COLOR;
  color_quad = pass3->CreateAndAppendDrawQuad<SolidColorDrawQuad>();
  color_quad->material = DrawQuad::SOLID_COLOR;

  // pass3 is referenced by pass2.
  RenderPassDrawQuad* rpdq =
      pass2->CreateAndAppendDrawQuad<RenderPassDrawQuad>();
  rpdq->material = DrawQuad::RENDER_PASS;
  rpdq->render_pass_id = pass3->id;

  // But pass2 is not referenced by pass1. So pass2 and pass3 should be culled.
  FakeLayerTreeHostImpl::RemoveRenderPasses(&frame);
  EXPECT_EQ(1u, frame.render_passes.size());
  EXPECT_EQ(1u,
            CountRenderPassesWithId(frame.render_passes, RenderPassId(1, 0)));
  EXPECT_EQ(0u,
            CountRenderPassesWithId(frame.render_passes, RenderPassId(2, 0)));
  EXPECT_EQ(0u,
            CountRenderPassesWithId(frame.render_passes, RenderPassId(3, 0)));
  EXPECT_EQ(RenderPassId(1, 0), frame.render_passes[0]->id);
}

TEST_F(LayerTreeHostImplTest, RemoveEmptyRenderPass) {
  LayerTreeHostImpl::FrameData frame;
  frame.render_passes.push_back(RenderPass::Create());
  RenderPass* pass3 = frame.render_passes.back().get();
  frame.render_passes.push_back(RenderPass::Create());
  RenderPass* pass2 = frame.render_passes.back().get();
  frame.render_passes.push_back(RenderPass::Create());
  RenderPass* pass1 = frame.render_passes.back().get();

  pass1->SetNew(RenderPassId(1, 0), gfx::Rect(), gfx::Rect(), gfx::Transform());
  pass2->SetNew(RenderPassId(2, 0), gfx::Rect(), gfx::Rect(), gfx::Transform());
  pass3->SetNew(RenderPassId(3, 0), gfx::Rect(), gfx::Rect(), gfx::Transform());

  // pass1 is not empty, but pass2 and pass3 are.
  SolidColorDrawQuad* color_quad;
  color_quad = pass1->CreateAndAppendDrawQuad<SolidColorDrawQuad>();
  color_quad->material = DrawQuad::SOLID_COLOR;

  // pass3 is referenced by pass2.
  RenderPassDrawQuad* rpdq =
      pass2->CreateAndAppendDrawQuad<RenderPassDrawQuad>();
  rpdq->material = DrawQuad::RENDER_PASS;
  rpdq->render_pass_id = pass3->id;

  // pass2 is referenced by pass1.
  rpdq = pass1->CreateAndAppendDrawQuad<RenderPassDrawQuad>();
  rpdq->material = DrawQuad::RENDER_PASS;
  rpdq->render_pass_id = pass2->id;

  // Since pass3 is empty it should be removed. Then pass2 is empty too, and
  // should be removed.
  FakeLayerTreeHostImpl::RemoveRenderPasses(&frame);
  EXPECT_EQ(1u, frame.render_passes.size());
  EXPECT_EQ(1u,
            CountRenderPassesWithId(frame.render_passes, RenderPassId(1, 0)));
  EXPECT_EQ(0u,
            CountRenderPassesWithId(frame.render_passes, RenderPassId(2, 0)));
  EXPECT_EQ(0u,
            CountRenderPassesWithId(frame.render_passes, RenderPassId(3, 0)));
  EXPECT_EQ(RenderPassId(1, 0), frame.render_passes[0]->id);
  // The RenderPassDrawQuad should be removed from pass1.
  EXPECT_EQ(1u, pass1->quad_list.size());
  EXPECT_EQ(DrawQuad::SOLID_COLOR, pass1->quad_list.ElementAt(0)->material);
}

TEST_F(LayerTreeHostImplTest, DoNotRemoveEmptyRootRenderPass) {
  LayerTreeHostImpl::FrameData frame;
  frame.render_passes.push_back(RenderPass::Create());
  RenderPass* pass3 = frame.render_passes.back().get();
  frame.render_passes.push_back(RenderPass::Create());
  RenderPass* pass2 = frame.render_passes.back().get();
  frame.render_passes.push_back(RenderPass::Create());
  RenderPass* pass1 = frame.render_passes.back().get();

  pass1->SetNew(RenderPassId(1, 0), gfx::Rect(), gfx::Rect(), gfx::Transform());
  pass2->SetNew(RenderPassId(2, 0), gfx::Rect(), gfx::Rect(), gfx::Transform());
  pass3->SetNew(RenderPassId(3, 0), gfx::Rect(), gfx::Rect(), gfx::Transform());

  // pass3 is referenced by pass2.
  RenderPassDrawQuad* rpdq =
      pass2->CreateAndAppendDrawQuad<RenderPassDrawQuad>();
  rpdq->material = DrawQuad::RENDER_PASS;
  rpdq->render_pass_id = pass3->id;

  // pass2 is referenced by pass1.
  rpdq = pass1->CreateAndAppendDrawQuad<RenderPassDrawQuad>();
  rpdq->material = DrawQuad::RENDER_PASS;
  rpdq->render_pass_id = pass2->id;

  // Since pass3 is empty it should be removed. Then pass2 is empty too, and
  // should be removed. Then pass1 is empty too, but it's the root so it should
  // not be removed.
  FakeLayerTreeHostImpl::RemoveRenderPasses(&frame);
  EXPECT_EQ(1u, frame.render_passes.size());
  EXPECT_EQ(1u,
            CountRenderPassesWithId(frame.render_passes, RenderPassId(1, 0)));
  EXPECT_EQ(0u,
            CountRenderPassesWithId(frame.render_passes, RenderPassId(2, 0)));
  EXPECT_EQ(0u,
            CountRenderPassesWithId(frame.render_passes, RenderPassId(3, 0)));
  EXPECT_EQ(RenderPassId(1, 0), frame.render_passes[0]->id);
  // The RenderPassDrawQuad should be removed from pass1.
  EXPECT_EQ(0u, pass1->quad_list.size());
}

class FakeVideoFrameController : public VideoFrameController {
 public:
  void OnBeginFrame(const BeginFrameArgs& args) override {
    begin_frame_args_ = args;
    did_draw_frame_ = false;
  }

  void DidDrawFrame() override { did_draw_frame_ = true; }

  const BeginFrameArgs& begin_frame_args() const { return begin_frame_args_; }

  bool did_draw_frame() const { return did_draw_frame_; }

 private:
  BeginFrameArgs begin_frame_args_;
  bool did_draw_frame_ = false;
};

TEST_F(LayerTreeHostImplTest, AddVideoFrameControllerInsideFrame) {
  BeginFrameArgs begin_frame_args =
      CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE);
  FakeVideoFrameController controller;

  host_impl_->WillBeginImplFrame(begin_frame_args);
  EXPECT_FALSE(controller.begin_frame_args().IsValid());
  host_impl_->AddVideoFrameController(&controller);
  EXPECT_TRUE(controller.begin_frame_args().IsValid());
  host_impl_->DidFinishImplFrame();

  EXPECT_FALSE(controller.did_draw_frame());
  LayerTreeHostImpl::FrameData frame;
  host_impl_->DidDrawAllLayers(frame);
  EXPECT_TRUE(controller.did_draw_frame());

  controller.OnBeginFrame(begin_frame_args);
  EXPECT_FALSE(controller.did_draw_frame());
  host_impl_->RemoveVideoFrameController(&controller);
  host_impl_->DidDrawAllLayers(frame);
  EXPECT_FALSE(controller.did_draw_frame());
}

TEST_F(LayerTreeHostImplTest, AddVideoFrameControllerOutsideFrame) {
  BeginFrameArgs begin_frame_args =
      CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE);
  FakeVideoFrameController controller;

  host_impl_->WillBeginImplFrame(begin_frame_args);
  host_impl_->DidFinishImplFrame();

  EXPECT_FALSE(controller.begin_frame_args().IsValid());
  host_impl_->AddVideoFrameController(&controller);
  EXPECT_FALSE(controller.begin_frame_args().IsValid());

  begin_frame_args = CreateBeginFrameArgsForTesting(BEGINFRAME_FROM_HERE);
  EXPECT_FALSE(controller.begin_frame_args().IsValid());
  host_impl_->WillBeginImplFrame(begin_frame_args);
  EXPECT_TRUE(controller.begin_frame_args().IsValid());

  EXPECT_FALSE(controller.did_draw_frame());
  LayerTreeHostImpl::FrameData frame;
  host_impl_->DidDrawAllLayers(frame);
  EXPECT_TRUE(controller.did_draw_frame());

  controller.OnBeginFrame(begin_frame_args);
  EXPECT_FALSE(controller.did_draw_frame());
  host_impl_->RemoveVideoFrameController(&controller);
  host_impl_->DidDrawAllLayers(frame);
  EXPECT_FALSE(controller.did_draw_frame());
}

TEST_F(LayerTreeHostImplTest, GpuRasterizationStatusModes) {
  EXPECT_FALSE(host_impl_->use_gpu_rasterization());

  host_impl_->SetHasGpuRasterizationTrigger(true);
  host_impl_->SetContentIsSuitableForGpuRasterization(true);
  EXPECT_EQ(GpuRasterizationStatus::ON, host_impl_->gpu_rasterization_status());
  EXPECT_TRUE(host_impl_->use_gpu_rasterization());

  host_impl_->SetHasGpuRasterizationTrigger(false);
  host_impl_->SetContentIsSuitableForGpuRasterization(true);
  EXPECT_EQ(GpuRasterizationStatus::OFF_VIEWPORT,
            host_impl_->gpu_rasterization_status());
  EXPECT_FALSE(host_impl_->use_gpu_rasterization());

  host_impl_->SetHasGpuRasterizationTrigger(true);
  host_impl_->SetContentIsSuitableForGpuRasterization(false);
  EXPECT_EQ(GpuRasterizationStatus::OFF_CONTENT,
            host_impl_->gpu_rasterization_status());
  EXPECT_FALSE(host_impl_->use_gpu_rasterization());
  EXPECT_FALSE(host_impl_->use_msaa());

  scoped_ptr<TestWebGraphicsContext3D> context_with_msaa =
      TestWebGraphicsContext3D::Create();
  context_with_msaa->SetMaxSamples(8);

  LayerTreeSettings msaaSettings = GpuRasterizationEnabledSettings();
  msaaSettings.gpu_rasterization_msaa_sample_count = 4;
  EXPECT_TRUE(CreateHostImpl(
      msaaSettings, FakeOutputSurface::Create3d(std::move(context_with_msaa))));
  host_impl_->SetHasGpuRasterizationTrigger(true);
  host_impl_->SetContentIsSuitableForGpuRasterization(false);
  EXPECT_EQ(GpuRasterizationStatus::MSAA_CONTENT,
            host_impl_->gpu_rasterization_status());
  EXPECT_TRUE(host_impl_->use_gpu_rasterization());
  EXPECT_TRUE(host_impl_->use_msaa());

  LayerTreeSettings settings = DefaultSettings();
  settings.gpu_rasterization_enabled = false;
  EXPECT_TRUE(CreateHostImpl(settings, FakeOutputSurface::Create3d()));
  host_impl_->SetHasGpuRasterizationTrigger(true);
  host_impl_->SetContentIsSuitableForGpuRasterization(true);
  EXPECT_EQ(GpuRasterizationStatus::OFF_DEVICE,
            host_impl_->gpu_rasterization_status());
  EXPECT_FALSE(host_impl_->use_gpu_rasterization());

  settings.gpu_rasterization_forced = true;
  EXPECT_TRUE(CreateHostImpl(settings, FakeOutputSurface::Create3d()));

  host_impl_->SetHasGpuRasterizationTrigger(false);
  host_impl_->SetContentIsSuitableForGpuRasterization(false);
  EXPECT_EQ(GpuRasterizationStatus::ON_FORCED,
            host_impl_->gpu_rasterization_status());
  EXPECT_TRUE(host_impl_->use_gpu_rasterization());
}

class MsaaIsSlowLayerTreeHostImplTest : public LayerTreeHostImplTest {
 public:
  void CreateHostImplWithMsaaIsSlow(bool msaa_is_slow) {
    LayerTreeSettings settings = DefaultSettings();
    settings.gpu_rasterization_enabled = true;
    settings.gpu_rasterization_msaa_sample_count = 4;
    auto context_provider = TestContextProvider::Create();
    context_provider->UnboundTestContext3d()->SetMaxSamples(4);
    context_provider->UnboundTestContext3d()->set_msaa_is_slow(msaa_is_slow);
    auto msaa_is_normal_output_surface =
        FakeOutputSurface::Create3d(context_provider);
    EXPECT_TRUE(
        CreateHostImpl(settings, std::move(msaa_is_normal_output_surface)));
  }
};

TEST_F(MsaaIsSlowLayerTreeHostImplTest, GpuRasterizationStatusMsaaIsSlow) {
  // Ensure that without the msaa_is_slow cap we raster unsuitable content with
  // msaa.
  CreateHostImplWithMsaaIsSlow(false);
  host_impl_->SetHasGpuRasterizationTrigger(true);
  host_impl_->SetContentIsSuitableForGpuRasterization(false);
  EXPECT_EQ(GpuRasterizationStatus::MSAA_CONTENT,
            host_impl_->gpu_rasterization_status());
  EXPECT_TRUE(host_impl_->use_gpu_rasterization());

  // Ensure that with the msaa_is_slow cap we don't raster unsuitable content
  // with msaa.
  CreateHostImplWithMsaaIsSlow(true);
  host_impl_->SetHasGpuRasterizationTrigger(true);
  host_impl_->SetContentIsSuitableForGpuRasterization(false);
  EXPECT_EQ(GpuRasterizationStatus::OFF_CONTENT,
            host_impl_->gpu_rasterization_status());
  EXPECT_FALSE(host_impl_->use_gpu_rasterization());
}

// A mock output surface which lets us detect calls to ForceReclaimResources.
class MockReclaimResourcesOutputSurface : public FakeOutputSurface {
 public:
  static scoped_ptr<MockReclaimResourcesOutputSurface> Create3d() {
    return make_scoped_ptr(new MockReclaimResourcesOutputSurface(
        TestContextProvider::Create(), TestContextProvider::CreateWorker(),
        false));
  }

  MOCK_METHOD0(ForceReclaimResources, void());

 protected:
  MockReclaimResourcesOutputSurface(
      scoped_refptr<ContextProvider> context_provider,
      scoped_refptr<ContextProvider> worker_context_provider,
      bool delegated_rendering)
      : FakeOutputSurface(context_provider,
                          worker_context_provider,
                          delegated_rendering) {}
};

// Display::Draw (and the planned Display Scheduler) currently rely on resources
// being reclaimed to block drawing between BeginCommit / Swap. This test
// ensures that BeginCommit triggers ForceReclaimResources. See
// crbug.com/489515.
TEST_F(LayerTreeHostImplTest, BeginCommitReclaimsResources) {
  scoped_ptr<MockReclaimResourcesOutputSurface> output_surface(
      MockReclaimResourcesOutputSurface::Create3d());
  // Hold an unowned pointer to the output surface to use for mock expectations.
  MockReclaimResourcesOutputSurface* mock_output_surface = output_surface.get();

  CreateHostImpl(DefaultSettings(), std::move(output_surface));
  EXPECT_CALL(*mock_output_surface, ForceReclaimResources()).Times(1);
  host_impl_->BeginCommit();
}

TEST_F(LayerTreeHostImplTest, UpdatePageScaleFactorOnActiveTree) {
  // Check page scale factor update in property trees when an update is made
  // on the active tree.
  host_impl_->CreatePendingTree();
  host_impl_->pending_tree()->PushPageScaleFromMainThread(1.f, 1.f, 3.f);
  CreateScrollAndContentsLayers(host_impl_->pending_tree(),
                                gfx::Size(100, 100));
  host_impl_->pending_tree()->BuildPropertyTreesForTesting();
  host_impl_->ActivateSyncTree();
  DrawFrame();

  host_impl_->CreatePendingTree();
  host_impl_->active_tree()->SetPageScaleOnActiveTree(2.f);
  LayerImpl* page_scale_layer = host_impl_->active_tree()->PageScaleLayer();

  TransformNode* active_tree_node =
      host_impl_->active_tree()->property_trees()->transform_tree.Node(
          page_scale_layer->transform_tree_index());
  // SetPageScaleOnActiveTree also updates the factors in property trees.
  EXPECT_EQ(active_tree_node->data.post_local_scale_factor, 2.f);
  EXPECT_EQ(host_impl_->active_tree()->current_page_scale_factor(), 2.f);

  TransformNode* pending_tree_node =
      host_impl_->pending_tree()->property_trees()->transform_tree.Node(
          page_scale_layer->transform_tree_index());
  EXPECT_EQ(pending_tree_node->data.post_local_scale_factor, 1.f);
  EXPECT_EQ(host_impl_->pending_tree()->current_page_scale_factor(), 2.f);

  host_impl_->pending_tree()->UpdateDrawProperties(false);
  pending_tree_node =
      host_impl_->pending_tree()->property_trees()->transform_tree.Node(
          page_scale_layer->transform_tree_index());
  EXPECT_EQ(pending_tree_node->data.post_local_scale_factor, 2.f);

  host_impl_->ActivateSyncTree();
  host_impl_->active_tree()->UpdateDrawProperties(false);
  active_tree_node =
      host_impl_->active_tree()->property_trees()->transform_tree.Node(
          page_scale_layer->transform_tree_index());
  EXPECT_EQ(active_tree_node->data.post_local_scale_factor, 2.f);
}

TEST_F(LayerTreeHostImplTest, SubLayerScaleForNodeInSubtreeOfPageScaleLayer) {
  // Checks that the sublayer scale of a transform node in the subtree of the
  // page scale layer is updated without a property tree rebuild.
  host_impl_->active_tree()->PushPageScaleFromMainThread(1.f, 1.f, 3.f);
  CreateScrollAndContentsLayers(host_impl_->active_tree(), gfx::Size(100, 100));
  LayerImpl* page_scale_layer = host_impl_->active_tree()->PageScaleLayer();
  page_scale_layer->AddChild(LayerImpl::Create(host_impl_->active_tree(), 100));

  LayerImpl* in_subtree_of_page_scale_layer =
      host_impl_->active_tree()->LayerById(100);
  in_subtree_of_page_scale_layer->SetForceRenderSurface(true);
  SetNeedsRebuildPropertyTrees();
  RebuildPropertyTrees();
  DrawFrame();
  TransformNode* node =
      host_impl_->active_tree()->property_trees()->transform_tree.Node(
          in_subtree_of_page_scale_layer->transform_tree_index());
  EXPECT_EQ(node->data.sublayer_scale, gfx::Vector2dF(1.f, 1.f));

  host_impl_->active_tree()->SetPageScaleOnActiveTree(2.f);
  DrawFrame();
  in_subtree_of_page_scale_layer = host_impl_->active_tree()->LayerById(100);
  node = host_impl_->active_tree()->property_trees()->transform_tree.Node(
      in_subtree_of_page_scale_layer->transform_tree_index());
  EXPECT_EQ(node->data.sublayer_scale, gfx::Vector2dF(2.f, 2.f));
}

TEST_F(LayerTreeHostImplTest, JitterTest) {
  host_impl_->SetViewportSize(gfx::Size(100, 100));

  host_impl_->CreatePendingTree();
  CreateScrollAndContentsLayers(host_impl_->pending_tree(),
                                gfx::Size(100, 100));

  host_impl_->pending_tree()->PushPageScaleFromMainThread(1.f, 1.f, 1.f);
  host_impl_->pending_tree()->BuildPropertyTreesForTesting();
  const int scroll = 5;
  int accumulated_scroll = 0;
  for (int i = 0; i < host_impl_->pending_tree()->kFixedPointHitsThreshold + 1;
       ++i) {
    host_impl_->ActivateSyncTree();
    host_impl_->ScrollBegin(BeginState(gfx::Point(5, 5)).get(),
                            InputHandler::TOUCHSCREEN);
    host_impl_->ScrollBy(
        UpdateState(gfx::Point(), gfx::Vector2dF(0, scroll)).get());
    accumulated_scroll += scroll;
    host_impl_->ScrollEnd(EndState().get());
    host_impl_->active_tree()->UpdateDrawProperties(false);

    host_impl_->CreatePendingTree();
    host_impl_->pending_tree()->set_source_frame_number(i + 1);
    LayerImpl* content_layer = host_impl_->pending_tree()
                                   ->OuterViewportScrollLayer()
                                   ->children()[0]
                                   .get();
    // The scroll done on the active tree is undone on the pending tree.
    gfx::Transform translate;
    translate.Translate(0, accumulated_scroll);
    content_layer->SetTransform(translate);

    LayerTreeImpl* pending_tree = host_impl_->pending_tree();
    pending_tree->PushPageScaleFromMainThread(1.f, 1.f, 1.f);
    LayerImpl* last_scrolled_layer = pending_tree->LayerById(
        host_impl_->active_tree()->LastScrolledLayerId());

    // When building property trees from impl side, the builder uses the scroll
    // offset of layer_impl to initialize the scroll offset in scroll tree:
    //  scroll_tree.synced_scroll_offset.PushFromMainThread(
    //                                   layer->CurrentScrollOffset()).
    // However, layer_impl does not store scroll_offset, so it is using scroll
    // tree's scroll offset to initialize itself. Usually this approach works
    // because this is a simple assignment. However if scroll_offset's pending
    // delta is not zero, the delta would be counted twice.
    // This hacking here is to restore the damaged scroll offset.
    gfx::ScrollOffset pending_base =
        pending_tree->property_trees()
            ->scroll_tree.GetScrollOffsetBaseForTesting(
                last_scrolled_layer->id());
    pending_tree->property_trees()->needs_rebuild = true;
    pending_tree->BuildPropertyTreesForTesting();
    pending_tree->property_trees()
        ->scroll_tree.UpdateScrollOffsetBaseForTesting(
            last_scrolled_layer->id(), pending_base);

    pending_tree->set_needs_update_draw_properties();
    pending_tree->UpdateDrawProperties(false);
    float jitter =
        LayerTreeHostCommon::CalculateFrameJitter(last_scrolled_layer);
    // There should not be any jitter measured till we hit the fixed point hits
    // threshold.
    float expected_jitter =
        (i == pending_tree->kFixedPointHitsThreshold) ? 500 : 0;
    EXPECT_EQ(jitter, expected_jitter);
  }
}

}  // namespace
}  // namespace cc